Nearly 20 years ago, halfway through the year 1995, I started to go over all things relating to biology, which had been my favorite subject in school. In 1969, having graduated from high school, I had gone on to college in order to study Biology, but I studied only three semesters. I withdrew and asked for a "general incomplete report", a device that allowed one to resume one's studies at any moment. I never went back.
What I did mainly was make an inventory of all groups, both plant and animal, going from one group to the next, until it seemed like there were no more surprises to be found, something I'd never had the patience to do so thoroughly. In the course of a year and a half I filled, with passages from many books, at a public library, nine small notebooks. I numbered the pages and managed to go beyond 1,500. Botany was examined somewhat hastily, yet here, too, several exceptional cases were found. It might be worth the while to add a botanical list, some fine day.
I started noticing that exceptional cases were showing up quite often, many of which were unique cases. Several hundred piled up. This became a recurrent theme like no other, and it furnished enough information to fill a book, yet there were doubts about its importance, so that time went by without this being more than a mere hobby.
The Age of the Net arrived and this allowed further gathering of unusual cases without having to go back to the library. They also appeared occasionally in the television documentaries or in books or magazines of my own. Certain websites, like AllExperts.com, that had scientists answering questions free of charge, helped to explain some matters that remained uncertain. It claims to be the oldest question-and-answer site on the Net, with more than two million questions answered so far.
Biologist Daryl Maddox at AllExperts encouraged me with the following words: "Your interest is exceptional and may well be worth a publication as you complete the listings. I am impressed with your in-depth analysis and suggest you continue to pursue this with the express goal of such a publication. Good luck to you."
That was three lustrums ago, back in 1999. The decision to upload it all onto the Net was due to the fact that having reached a certain age one starts to wonder how much time remains. It would be regrettable for all that work to go to waste, even if it was only for personal amusement. Moreover, it looks like nobody else has done the job systematically. The nearest thing to this is the illustrated books for children with titles like Amazing Animals.
In my school days, back in the Fifties and Sixties, one was taught that there were three kingdoms of Nature: Mineral, Plant and Animal. Living organisms were either plants or animals. Some, like Euglena, seemed to be both. Not much later alll that changed. Now it's five kingdoms, rather than only two: animals, plants, Fungi, Monera and Protoctista (not Haeckel's Protista).
It was now clear that it was no longer adequate to keep thinking that fungi, which are not primary producers but break down food produced by others, were plants. Furthermore, the electronic microscope led to the discovery that the fundamental difference was between procariotic cells, which lack a nucleus, and eucariotic cells, which do have one. Bacteria, all of which are unicellular, comprise the Kingdom Monera, the realm of procariotic cells. Members of Kingdom Protoctista are all eucariotic and either unicellular or multicellular, but they're all aquatic. Eucariotic cells are (up to a thousand times) larger and far more complex.
In order to simplify matters, I made my lists following the two-kingdom model. In my times everything, and not only classifying Nature, was far simpler.
Deciding to place the human race among the other animal species was also unorthodox. What justifies this choice is its arrogance, which is what explains a cruel treatment of its "younger" siblings, which are actually far older and wiser, for they have privileged access to information beyond its reach. Consequently it appears in the lists of cases, but only occasionally, and even so the tiny number of such cases is entirely out of proportion, the said species being merely one among many millions of species. (Some say maybe 30 million, others up to 100 million, whereas not even 2 million have been described so far.)
A few cases remain uncertain, but fortunately these, too, are a weeny minority. They are pointed out with a question mark in parentheses. Only specialists on the pertinent branch of zoology could tell us what to do about them.
Readers are asked to tell about any additional examples they happen to be aware of. The purpose is to continue the gathering indefinitely.
The lists will be displayed first, then cases will be explained one by one, with the relevant passages, which belong to about one hundred sources. On classifying the cases it was discovered that most of them belonged to four categories (the first four of the list below). It was seen as convenient for some of them to be placed in more than one category, or in more than one section within the same category. The following is the series of categories, placed according to the number of cases, with the largest one at the top of the list.
II. Morphology (= anatomy)