Initiative in Evolution

English judge. This is presented to the jury of the biological world and they are still considering it. Their verdict and his sentence are not yet delivered, and it

dge to the effect that in the case Lamarck v. Weismann the plaintiff has won. As in the Great War the Old Contemptibles held their line with the utmost difficulty against

othesis of modifica-tion inheritance. The words are:28 “The neo-Lamarckians have to show that the phenomena they adduce as illustrations of modifica-tion-inheritance cannot be interpreted as the results of selection operating on germinal variations. In order to do this to the satisfac-tion of the other side, the neo-Lamarckians must prove that the

had used Professor Thomson’s term “modifications” instead of “characters” in the statement of this doctrine much confusion and evasion of plain facts would have been avoided, and y

d demanded from the neo-Lamarckians is the produc-tion of a few well-attested and verified facts, and, as he admits himself, then it must follow as the night the day that his followers will surrender his characteristic dogma. The more cautious leaders and teachers of the day say that this has not taken place and ask for facts, more facts and still more facts, and this attitude is both judicious and judicial, for example in a teacher so eminent as Professor J. Arth

Ques

ientific jury to-day tw

f an individual organism, occurring as a

the cause

er No. 2, for from the present point of view the two stand or fall together in the study of Initiative in

ions from the Lamarckian standpoint, for it is hardly conceivable that Nature would neglect so simp

d’appui in the process is earnestly desired by many workers and that Weismann’s dogma

hey can with the tools and the materials which exist, and I agree with Professor Thomson in his remark on Misunderstanding No. 1, “that our first business is to find out the facts of the case, careless whether it makes our interpreta-tion of the history of life more or less difficult,”32 but I am persuaded that he will not treat lightly such a statement, from such a source, on such a subject as that I have quoted from Professor McDougall. As to his second statement on the same page “that in the supply of terminal variations, whose transmissibility is unquestioned, there is ample raw material for evolution” it is important as an opinion, and no more, and there is in the pre

Problem

ory of life; there is no question of the “relative importance of natural selection and the Lamarckian factors in organic evolution,” though such a question may arise when

stion of Mendelian analysis, nor as to the distribu-tion of either mutations on the one hand, nor of minute fluctuating variations on the oth

lems Con

re alone the white light of science shines. Here the writ of a priori does not run. The spirit of inquiry makes its challenge to every presupposi-tion and every assertion in its province—even those of current science. I have shown that this particular assump-tion of the natural man was firmly challenged by Weismann, who was not the first, but the greatest, biologist to teach that modifications are not transmitted. Accordingly, agreeable and convenient as it would be to assume the Lamarckian hypoth

ns in certain mammals whose structure and mode of life are intimately known, and whose ancestry is little in dispute.33 The most convincing of thes

rganic evolution which might claim a share in the produc-tion of such

l Selectio

ual Se

Cellular Sele

inal Se

ccording to Mend

tance of

count, and on paper, may loosely be said to be ‘correlated’ with it, is to be ruled out. That would be tantamount to saying for example, that, because an animal must lie down in a certain attitude when it rests, or walk or run in a certain manner, in other words that it is useful to exist, certain modifications claimed to be due to these fundamental parts of existence must be excluded from the inquiry. The neo-Darwinian is not a critic easy to be entreated, but that he would not claim. Let me take one example of what I mean. A short-haired dog will spend a considerable part of its daily life, and presumably a long line of ancestors did so too, lying with its forelegs planted in front

idence forthcoming because it is correlated with the useful “character” of lying in a certain attitude. Such a phenomenon, many similar to which will be seen later, had at any rate an origin de novo at some time in the ancestral st

elat

associated with the work of the biometricians, and a few examples from Dr. Vernon’s book will show how far this concep-tion of correla-tion is removed from the literal applica-tion of Professor Thomson’s formula. Dr. Vernon treats of such phenomena as the correla-tion of the long heads of greyhounds with length of legs, contrasting them with the shortened heads and legs of bull-dogs. He describes also the correla-tion in man between the stature and length of forearm from elbow to tip of middle finger, correlated measurements of crabs, of external structures of prawns, the tufts of Polish fow

hysiology rather than anat

small modifications cannot be governed by selection and are not correlated with useful characters. It will be shown later that Professor Thomson’s stringent conditio