4:00 P.M.

December 3, 1970

To Replicate

by Wilbur Norton Vroman

Assembly Room, A. K. Smiley Public Library

This paper could have been titled, To Reproduce. In the literature on reproduction, biologists use, as do all professionals, a language of their own; the word, 'replicate' indicates to make a copy of itself, to reproduce.

Three related themes run through the paper:

1. The curiosity that all people have concerning reproduction as it is illustrated by experiences in my own childhood.

2. The need to reproduce sexually if a species is  to have those slight variances in offspring  necessary for-it to adapt to changing environments.

3. The emergence of bizarre and divergent sexual  behavior among some of the invertebrates.

T 0 R E P R 0 D U C E

Several years ago I was invited to an evening meeting of some very learned writers. In this group of writers was such talent as Dr. Lawrence Nelson, Dr. Louis Mertins, and Mrs. Bess Adams, Glenn's capable wife. With the inclusion of the four-letter word in contemporary writing and with the anticipation of the sex act as the main course, rather than the spice, in best selling fare, I did not expect much embarrassment over the program to be evidenced by the members of this writers' guild. The program was to be an illustrated talk on sexual reproduction. There were many who were not writers at this meeting, however. With me was my wife, who had lived the sheltered part of her life in a Baptist parsonage. There were in the group several spinster ladies and some missionaries' widows from Plymouth Village. There were several prudes and shy perons like myself, who blush and who are compelled to turn our heads when walking through the lingerie department at Harris'. These could be expected to be somewhat un­comfortable if just the two words, "sexual reproduction" were to be said aloud.

If a picture is worth a thousand words, then, at that meeting, the words "sexual reproduction" must have been said in the tens of thousands of times; it was a program of colored slides on sexual reproduction, on insects and other invertebrates in the act of copulation. It should have embarrassed my sheltered wife, the spinsters, the missionaries' widows, and even me, the declared shy prude. It did not. I was more than interested and pleased by the pictures.

The pictures were shown by one of Redlands' own, a gentleman of English birth, and they were shown with a delicacy which made the presentation almost one of poetry; and that is not always the case with many of Ed Fisher's presentations. I would that my words had the same delicacy and refinement and beauty in composition that Mr. Fisher has in his pictures since I have chosen the same subject, Sexual Reproduction, the need for it in nature, and the methods of some of the invertebrates.

When I was a very young boy I was given a Gilbert Chemistry set by Santa Claus. Among the chemicals was oxalic acid. I now made a solution of the powder and placed it in a saucer. In a few days, I was surprised to find some beautiful needle-shaped crystals in the dish. I ground the crystals to a powder, dissolved them and, in a few days, again found the same needle-shaped crystals.

With pre-adolescent scientific enthusiasm, for an entire summer I ground oxalic acid to a powder, dissolved the powder and formed crystals. I wanted to see if, just for once, some other crystal shape would be formed. Of course, none did; but I did prove something to myself: oxalic acid crystals produce only oxalic acid crystals unless something new is added. Second, oxalic acid crystals do not survive if they are ground, or heated, or have water poured on them. They did reproduce themselves, but they did not produce variants nor additional crystals. And, while they grew, they did not live. And, while they were always oxalic acid crystals, they could not be formed unless oxalic acid was already present in the solution.

This juvenile bit of research is a far cry from the sophisticated research into the life processes made by today's molecular biologists. They have divided the cell into a series of components, each of which seems to perform its unique process, be it to take food in and convert it into useable energy and to excrete waste materials, or to take food in and convert it into complex proteins and nucleic acids and, through DNA, deoxyribonucleic acid, to reproduce, ? to replicate is the term biologists use, ? to replicate the cell and to pass omits inheritance. It is beyond my comprehension.

My oxalic acid did seem to replicate itself but it lacked something, the life process. It lacked the ability to take in chemicals and from within itself to convert the chemicals to oxalic acid.

In my post-adolescent days I received a small microscope as a Christmas present, ? I no longer believed in Santa Claus. I could watch the single-celled animals, the amoebas and paramecia, move about, engulf food and grow. I was most excited when I saw an amoeba split into two daughter cells, ? or, should they be called "sister cells"?

The water dried on the microscope slide and as it dried, all of the sister amoebas died. They were unable to adapt to the changing environment. Perhaps, if there had been a slight change in their structures, if there had been some change in the factors for inheritance, they could have adapted to their dry environment - gone to sleep - and recovered when moisture returned.

I was excited: I had seen the amoeba reproduce; however, it was by fission and it had had its limitations, there had been no sexual reproduction that could have changed the factors for inheritance. The inheritance was from a single parent and, with the exception of slight mutations, the amoebas would produce daughters, or sisters, that were literally "chips off the old block"; they had been doing it for millions of years, and would continue to do so for millions of more years unless the environment becomes too polluted.

Living things are comprised of millions of cells, are most complex, and specialized structures. This fission method works satisfactorily for the simple cell, but it becomes a cartoon when it is applied to a whole complex animal. Picture an elephant splitting itself through fission, through asexual reproduction, into two faithful, better than Xerox, replicas of itself:

The fission process works well in higher plants and animals, but only for the individual cell units; the corpuscle splits into two corpuscles, et cetera. It produced little or no variance in individual cells so that they could adapt to changing environments. To divide a many-celled flea, or fly, or elephant, or man, by splitting,becomes ridiculous. Unless Mother Nature maintained a constancy and a contentment with the one-celled creatures, she would have to develop variances within creatures and less awkward methods of reproducing. Through one of the eons of the millions of eons available, two types emerged: the rooster and the hen, the bull and the cow, the boy scout and the girl scout, the male and the female. Necessary sex reared its ugly, and more often, its beautiful head.

The word "sex" is derived from the Latin, sectus, which means separation. It defines precisely the division of a species into two types, the male and the female. The male produces the spermatozoa, the sperms; the female produces the ova, the eggs. The union of these two is the method by which Mother Nature resolves the problems created by changing environments and the reproduction of complex creatures.

In asexual reproduction, such as I had observed in the amoeba, the same individual persists indefinitely; the thousandth generation is the first generation. There is practically no variance between individuals and very little ability to adapt to changes. "The sexual processes, on the other hand, are not only far more general, but imply a fresh combination of the gametes, the spermatazoa and the ova        (when) they are brought together in the act of fertilization. In this act a new individual with a new potential is formed, one that bears the hereditary characters of both parents associated in a new arrangement different from that of either progenitor."

With certain refinements, the spermatazoa and the ova which carry the in­heritable factors of the parents, evolve in the testes and the ovaries by a simple cell division, much as the amoeba on my slide had divided. What does happen in the cell division of the gametes is almost miraculous: The process is called meiosis. The inheritance factors are carried in a part of the cell chromosomes ?

so called because they are bodies within the cell that can be dyed. Without going into details, the chromosomes divide and, in a process common to all germ cell division, the number of them is reduced to one-half through a shuffling arrangement. In the opposite sex, the gametes have their chromosomes reduced to one-half. Meiosis varies between the sexes so that many times as many spermatazoa are formed as are ova. The male factor is ex­pendable: At the time of fertilization, the gametes are fused to form a cell with a full complement of chromosomes; and variability and possible adaptability to a changing environment takes place.

The methods by which the union of the spermatazoa and the ova take place, fertilization, must have exhausted Mother Nature's ingenuity. They are various, and to man, strange and interesting. They may be casual and haphazard as in the oyster, or they may involve the ritualistic and complex lovemaking of man.

For most of the invertebrates that live in the sea, fertilization may con­sist of the random shedding of the sperms and the eggs. In this external ferti­lization, vast numbers of eggs and sperms must be produced to increase the odds of a sperm reaching an egg. There is a vast waste of the gametes and, since the eggs carry a food supply, a tremendous drain has been placed upon the female.

Mother Nature has been given millions of years in which to develop efficient methods by which the sperms and the ova can be brought together. In the case of the careless and haphazard oysters, some will release their sperms and ova only in the presence of certain chemicals in the ocean. Those oysters in the immediate area of the chemical will be stimulated to shed their gametes. Much is left to chance even with this remarkable advance.

A more precise method of stimulation of the sperms and ova and fertilization is evidenced by the spawning of the grunion on our Southern California beaches. The stimulant is the tide. When the tide is right, the grunion come to the beaches. The male grunion encircles the female and fertilizes her eggs as she lays them. The female lays the eggs in the sand at the correct distance up on the beach to prevent them from being washed out with the waves and yet they are laid close enough to the water's edge so that the next highest tide, about a fortnight hence, will carry the newly hatched grunion out to sea.

There is still much of a chance that many eggs will not hatch, but this method of one of the vertebrates is much better than that of the oyster, an invertebrate.

Another improvement in the hit-and-miss method of fertilization was made by the sea urchin that used to be common on our local beaches: a mature sea urchin releases a stimulant when either ova or sperms are ready; the presence of this stimulant causes all sea urchins close by to ripen and release their ova and sperms at about the same time. It becomes epidemic: Fertilization is more assured by this method. There is, however, a great waste of fertilized eggs. Mother Nature probably used a couple more million of years to develop more efficient mothods; and she developed many methods between the random shedding of ova and sperms as in the oyster, the more specialized and precise method of shedding of sperms and ova in the sea urchin and grunion, until she developed true internal fertilization.

When I became a young man, I moved to California and, as are all Midwesterners, I was fascinated by the creatures that abound in the salt water beaches. I liked to probe into the mouths of the many-colored anemones.

The extended tentacles would close tightly over the mouth and the anemone would lose its color and become indiscernable on the shallow floor of the ocean pond. While the anemone does not have true internal fertilization, it seems to be heading in that general direction.

If a sea anemone is cut in half, it shows an internal central cavity. The ripe eggs are discharged into its own central cavity by the female anemone. When this is done a chemical stimulant is released. The free swimming sperms of other anemones are attracted by this stimulant and move into the mouth of the female and thence into the central cavity to fertilize the eggs. The fertilized eggs remain in the female, develop, and, at a certain stage "hatch" and swim out of the mouth of the female under their own power.

Dr. Stillman Berry of our club may have to verify this, but it is my understanding that the reproduction in clams is similar to the reproduction in the anemones.

My span of life has been so long that I witnessed, in my early childhood, the last of the medicine shows. I can remember the vendor of some mysterious elixir holding up a bottle that he professed contained a five foot tapeworm that had come out of the intestine of a boy, a boy who had been treated with the all-powerful elixer that the "medicine man" was vending. The bottle was passed around; it was repulsive and yet fascinating to me. In my nightmarish sleep that night, I had convinced myself that there was not such a creature as a tapeworm. (My mother had assured me that the medicine man was a fake.) It was not until a course in physiology warned against under-cooked pork that I believed in the existence of a tapeworm.

The life cycle of the tapeworm is an interesting adaptation to sexual repro­duction. The host animal, the pig, in its routing, swallows fertilized eggs of the tapeworm. The eggs hatch within the body of the host animal and develop

into tapeworms. The head segments of the tapeworm have the male organs and tail pieces, the female organs and the eggs. The mature sperms are set free into the intestine. They swim down and are passed along by the natural con­tractions of the intestine until they find a tail segment of a tapeworm that is full of mature eggs. Fertilization takes place in this segment; the seg­ment breaks off from the parent animal and is passed out of the host's body to the ground. And the cycle starts again.

This fertilization of the eggs by the sperms seems to be internal fer­tilization. (It is internal to the pig.') It is not internal fertilization. In true internal fertilization, the male places the sperm into the female's tract. In true internal fertilization, while it may not seem so to human eyes and human values, some sort of preliminary courtship is necessary.

Internal fertilization is possible only if there is a cooperative female even within the lower animals, the invertebrates. The female must be wooed by the male into cooperation, into a willingness to mate. As a part of this courtship, the female must be maneuvered into a position where she can re­ceive the sperm from the male. Courtship is necessary to have the female both willing and able to have internal fertilization.

There are many forms that courtship and internal fertilization take. An unusual type of courtship is that of the mole crab:

The mole crabs of the Atlantic Coast go through a ritual which induces the female crab to stay still long enough for the male to deposit his sperms. One pair of the male's legs are adapted for holding on to the female. When the female comes out of her burrow he holds on to the female long enough for him to weave a ribbon full of sperms on her underside. When the female lays her eggs they come into contact with the sperms in the ribbon. While this ritual is a form of courtship, it is not true internal fertilization.

Lobsters have a different type of courtship from crabs. The sperms are not placed in ribbons on the female's underside. "During mating, they are transferred into a special receptacle in the female's body where they are stored until she lays her eggs. To get these sperms stored is a difficult procedure. Through a courtship procedure, the male gets the female to lie on her back. He locks her legs and pincers with his large claws. His first pair of swimmerets have been formed into a duct. These are placed into the female's receptacles. The male has to use a pair of his walking legs to direct these modified swimmerets into the female's receptacles. After they are inserted, the sperm and mucous are passed into this storage receptacle. Having placed his sperm, the male lobster goes away.

"The female rights herself and waits until she is ready to lay her eggs. When she lays her eggs she also squeezes the sperm from her storage receptacle. She literally mixes the sperms and ova with her swimmerets. She carries the fertilized eggs around with her for ten months, until they finally are hatched." While the sperms are placed by the male inside the female, in the lobster, as in the mole crab, fertilization is external.

In what seems to man as cruel, one of the sea worms has developed a courtship ritual to assure internal fertilization. Through an external stimulation at spawning time, the female bites off the tail segment of the male during the mating rites. This segment contains the mature sperms. For­tunately, the male can replace the lost section by parthogenic reproduction. The male has the gruesome pleasure of watching the female eating his tail section: He'll have his revenge later, however. After the female's digestive juices have dissolved the male segment, the spermatazoa are freed into the intestine of the female. Aggressive sperms that they are, they bore through the wall of the intestine into the body cavity of the female. Within this cavity, they find the ripe eggs and fertilize them. Then, for some reason -- and here is where the male gets his revenge -- the female's body splits and the eggs escape into the sea. This is an example of courtship with internal fertilization.

Fifty years ago I was a Boy Scout. On our scout hikes we liked to go swimming in the nude in the Little Vermillion River. I had fun swimming in the old swimming hole, but when I came­out, I found that leeches had fastened themselves to my legs. To this day, there are few things as repulsive to me as a leech. And its sex life is just as repulsive. The male leech's sperms are enclosed in a sac. The sac and the sperms together are called a spermatophore. This spermatophore is glued, by the male leech, on to some part of the female's back. There is an irritant in the spermatophore which causes an ulcer to form on the skin of the female leech. The sperms swim out of the spermatophore through the open sore into the body of the leech. The ulcer heals over. The sperms, now in the body of the female leech, travel to the ovaries, where they fertilize the eggs. What an unattractive way for an unattractive invertebrate to perform internal fertilization)

Dr. Michelmore of England, in her book, Sexual Reproduction, writes of a "strange animal called Peripatus, intermediate . . . .between the segmented worms and the insects. Some forms of Peripatus attach a spermatophore to the female's back just as the leech does. Again an ulcer forms and the sperms enter the female's body cavity, making for the ovaries. The sperms appear to have a function that is an addition to the functions of the sperms of the leech. The first sperms to arrive cause ovulation to take place, then they die. Fertilization takes place only if the sperms from an­other spermatophore arrive.

Other varieties of Peripatus have improved on this method of mating. Sometimes infections are caused by the ulcers. While it still is unpleasant, one of the methods of mating does lessen the risk of infection. The male's reproductive duct ends in a sharp spine which he drives through the female's skin. He then places the sperms directly in the female's body cavity and the sperms travel to the ovaries.

I am always amazed at the number of earthworms that dry up on Redlands' sidewalks after each heavy rainstorm. They must be very prolific. The earth­worm has an unusual method of mating:

The earthworm is a hermaphroditic animal; it is both sexes. Since it is hermaphroditic, any other earthworm will serve as a mate. The earthworm simply crawls across another earthworm. It is a matter of maneuvering until the sperms of one of the worms can get to the eggs of another and vice versa. The earthworm has no arms or legs to hold itself into mating positions. It was necessary to develop some other technique to hold two earthworms together.

In an elementary biology class in high school, I had to dissect an earthworm. There is one section which looks like a little saddle on the worm. When the worms mate this saddle adheres to the ninth and tenth segments of the other worm. This sticking together of the saddle of one to the gonad sections of the other is accomplished by driving bristles into the other worm. A groove is formed between the worms. During mating, the sperms travel in opposite directions down the groove to the ovaries of the other worm. After fertilization, the worms separate. The mucous material forms a case around the eggs and each worm. The case works forward and slips off the head of the worm to form a capsule containing the eggs.

Mrs. Michelmore cites another odd method of mating. On the Pacific Coast, there is an hermaphroditic shell-less snail called the sea hare. "In the breeding season, one sea hare mounts another and they mate. Unlike the earthworm they do not exchange sperms. Where the procedure is unusual is that the top sea hare, itself, may be mounted, so that it is giving sperm to sea hare A and at the same time receiving sperm from sea hare C. The process becomes somewhat bizarre when as many as seven or eight animals become involved at once, the final touch being when the one at the head of the line swings around to mount the one at the tail, forming a strange reproductive circle." 4 Who is doing what to whom!!!

While the methods of mating cited above may seem crude, ridiculous, or even cruel, some of the mating procedures of invertebrates develop a refinement and gentleness.

Pseudoscorpions are related to spiders. Before they mate they perform a dance that is very involved and in which both mates play a part. The male grasps the female with his pincers and holds her. He then secretes a spermatophore containing his sperms. It is shaped like a round-headed map pin. The male manipulates the spermatophore until it is directly beneath a sexual pore on the female. The female opens her sexual pore and takes the spermatophore that the male is holding, into the sexual pore and into her body cavity. Once near the eggs, the spermatophore releases the sperms to fertilize the eggs.

In my daydreaming days, I would lie on my back and watch dragonflies hover around my mother's lily pool. Sometimes a joined pair, in tandem formation, would land. I knew they were mating but I did not know how it was being done. I actually had the two sexes reversed. After considerable acrobatics, the dragonflies got into a tandem position. After landing, it was the female who bent her body forward and inserted into a pore on the male.

In this pore was a spermatophore. The male dragonfly held onto the female until all of the sperms in the spermatophore had been released into her body. Instead of the sperms being placed in the female dragonfly by the male, it was the sperms being taken out of the male dragonfly by the female.

I do not remember any land snails in my growing-up days in Illinois. One of my first experiences with them was in observing a gentle neighbor lady.in Red I watched her wandering around in her iris bed one night with a flashlight. I asked her if I could help her find something. She told me that she was killing snails. Armed with a box of Morton's salt, she would find a snail with her flashlight and then she would sprinkle salt on it. I, too, was fascinated by the way the snail would boil and dissolve.

It was not until I had seen Ed Fisher's pictures that I learned of the cupid's dart method of mating of the hermaphroditic snail. Quoting from Susan Michelmore: " . . . .the land snail also goes to great lengths to ensure reciprocal mating. In fact, the mating of the snail has some points in common with that of the leech described earlier in that the sperms are contained in spermatophore and the animals stimulate one another by hypodermic injection. In the case of the snail it is not the spermatophore that is injected: the process is even more complicated. At the end of their reproductive tracts,snails have a dart sac which contains the dart,a sculptured calcareous weapon, which they can eject at will. When two snails are almost in contact, just prior to mating, they expel their darts with great vigor from the openings of their female ducts into their partners' bodies. These darts enter with such force that they often become imbedded in the animal's gut or other internal organs. This drastic action seems to provide sexual stimulation and they approach one another and exchange spermatophores."

The spermatophores are stored in the female parts of the snail until the ova are ripe. The covering  of the spermatophore has gradually dissolved and the sperms are released to fertilize the eggs.

The development of the spermatophore was a great advance over the random scattering of sperms. There are still many hazards in transferring a bag of sperm from the male to the female. The future of the species could be more assured if a pipeline could be developed from the male to the female. Through the years, Mother Nature improved the process of reproduction " . . . .by the development of the end part of the male's reproductive tract into a special mobile sperm-carrying duct, the penis. There is a corresponding modification . of the female's duct to form a special pocket, the vagina, into which the penis fits."

This type of mating is not too common in the invertebrates although it is found in insects. To human eyes, mating of insects often seems most awkward and complicated. The penis of insects generally points backward and must be reversed in direction before it can enter the female. The simplest of the contortions necessary before insects can mate is for the male to alight on the female's back and then to curve his stomach around to point the penis forward.

An insect's penis is an armored, rigid organ. In addition, in insects, for some reason, the bottom surface of the penis generally has to be the uppermost surface when entering the female's vagina. The sex organs also have projections and bristles on them. It is also important that the female insect's body remain undistorted. All of this seems unnessarily complicated yet it is a method by which Mother Nature has maintained the many species of insects.

This paper does not intend to carry sexual reproduction beyond the in­vertebrates. It is of interest to note that birds and reptiles also have internal fertilization and that some of them have developed a penis to as­sist in this process. Some lizards, all flightless birds, and ducks have a well developed penis.

I was surprised, not so many years ago, to come across a case in a museum in Salzburg, Austria, that contained a collection of penis bones. I had not known until then that in some mammals, where the mating period is relatively long, a penis bone has been developed to maintain the rigidity of the penis. These bones are found in wolves, dogs, foxes, mink, walrus, and the whale.

This paper has attempted to show that the consistent reforming 8f identical crystals from an oxalic solution is not reproduction. It has attempted to show that to reproduce by fission may work adequately for simple organisms, but it would not work for a complex elephant. It has attempted to show that there must be an opportunity for the re-combination of the factors of inheritance if an animal is to adapt to changing environments. It has attempted to show that internal fertilization is a more efficient method of conserving sperm and eggs than is the random scattering, as in the case of some of the sea creatures.

This paper has hinted that Mother Nature, in a seeming lack of direction, has developed many bizarre and cruel methods of mating, both in courtship and in the fertilization of the eggs. It has also hinted that this lack of direction has resulted in the many species of insects. In review: this paper has told of sexual reproduction in oysters, grunion, sea urchins, anemones, tapeworms, crabs, lobsters, sea worms, leeches, Peripatus, earthworms, sea hares, pseudoscorpions, snails, dragon flies, and insects.

I am glad that I am a naked ape; but what if I had been a horse fly: