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Suppose that it has taken five hundred years to form the greyhound out of his wolf-like ancestor. This is a mere guess, but it gives the order of the magnitude." Now, if so, "how long would it take to obtain an elephant from a protozoon, or even from a tadpole-like fish? Ought it not to take much more than a million times as long?" Mr.
Apart, however, from this scientific objection to evolutionism, there is another, derived from the undue admixture of ethical notions in the very idea of progress from which evolutionism derives its charm. Organic life, we are told, has developed gradually from the protozoon to the philosopher, and this development, we are assured, is indubitably an advance.
Like the solitary protozoön, each member leads a complete life in and by itself, equivalent to that of every biological unit. It obeys the two great laws already laid down, but in addition it seems to be required to remain with the others for some mutual good.
The primal duties of each family are unchanged, and their biological activities are identical, as in the protozoön colony of Vorticella or in a pack of wolves; but certain new relations are established.
The egg, in the modern physiological sense of the word, did not make its appearance until the descendants of the unicellular Protozoon had developed into multicellular animals, and these had undergone sexual differentiation.
It was held, following Cuvier, that the beings of the animal kingdom had been created in accordance with five preconceived types: the vertebrate, with a spinal column; the articulate, with jointed body and members, as represented by the familiar crustaceans and insects; the mollusk, of which the oyster and the snail are familiar examples; the radiate, with its axially disposed members, as seen in the starfish; and the low, almost formless protozoon, most of whose representatives are of microscopic size.
Unfortunately it is the philosopher, not the protozoon, who gives us this assurance, and we can have no security that the impartial outsider would agree with the philosopher's self-complacent assumption.
Quite lately the mnemic theory has been claimed by Rignano in his Scientific Synthesis as a complete explanation, in forgetfulness of the fact that even the all-powerful protozoon can only remember what has passed and could certainly not remember that it was some day going to breed a man.
These are the terms of the comparative array of psychology which are to be separately examined and classified, and to be brought into an evolutionary sequence if common-sense directs us to do so. Let us begin our comparative study with an example of the simplest animals that consist of only a single cell, such as the little protozoon Amoeba.
Human ethical conduct differs from insect and protozoön ethical conduct only in the element of a participation in the process by the explicit consciousness of man that he has definite obligations to others; and this distinguishing characteristic is the direct outcome of an evolution which adds reflection and conceptual thought to a mental framework derived from prehuman ancestors.
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