THE LAMARCKIAN PRINCIPLE 43 



I am unable to assent to either of these propositions. Indeed, 

 one of the chief objects of this book is to show that the 

 Lamarckian view has no basis in fact and that it offers no ex- 

 planation of the phenomena of animated nature. I have, there- 

 fore, set down some of the chief difficulties with which the 

 Lamarckian is confronted. Most of them he has had to face 

 before and has dealt with, at least to his own satisfaction. 

 Others, I believe, are new enemies to him. 



Suppose that any organism has been modified by exercise or T h e 

 by some change in the conditions under which it lives. How is difficulty 

 the modification to be transferred to the reproductive cells and f ere nce 

 so reappear in the offspring ? iTdri* 



In Protozoa, since they consist only of a single cell and organ to 

 multiply by fission of the entire organism, it is easy to see that t , he r e P r - 



. ..; V ductive 



inheritance is a much simpler matter than it is in the case cells 

 of creatures higher in the scale. The experiments which Dr 

 Dallinger made with monads may seem, till they are carefully 

 considered, to prove that the Protozoa at any rate can transmit 

 the qualities they acquire. 1 He found that when the water in 

 which they lived was raised from 60 to 73 F. their vitality and 

 productiveness were much reduced. But after being kept at 

 this temperature for about two months they recovered their 

 vigour. After this they were gradually trained to live at 78 F. 

 "Then a long pause was necessary, and during the period of 

 adaptation a marked development of vacuoles, or internal watery 

 spaces, was noticed, on the disappearance of which it was 

 possible to raise the temperature higher. Thus, by a series 

 of advances, with periods of rest between, a temperature of 

 158 F. was reached. It is estimated that the research extended 

 over half a million generations." 



This experiment, like all the evidence adduced in support 

 of Lamarckism, admits of a non-Lamarckian interpretation. 

 Natural Selection was no doubt at work. Many individuals 

 (I am obliged to dignify these fissiparous creatures by this 

 name) perished because they were unfitted to the changed 

 conditions. This and the acclimatisation of individuals is all 



1 See Lloyd Morgan's Animal Life and Intelligence, p. 147, from which I quote. 



