1899] A ZOOLOGIST ON THE PRINCIPLES OF SCIENCE 427 



True it is that this way of looking at the case brings in the direct 

 action of the environment just as much as ever, and that everything 

 depends on this and on the fundamental properties of protoplasm, or, 

 if you will, living protoplasm (we know no other). Thus, by accept- 

 ing the contentions of Dr. Brooks, I am led to the very position he is 

 trying to attack. 



Here seems the place to allude to two passages much further on 

 in the book (p. 187). "A living thing is a being which responds to 

 the stimulus of one event in such a way as to adjust its actions to 

 other events of which the stimulus is the sign, and as all that have 

 not thus responded have been exterminated in the struggle for exist- 

 ence, the adjustment of the survivors is no more than might have been 

 expected." " They who assert that it [natural selection] is inadequate 

 because it fails to show why beneficial response should ever follow a 

 stimulus, and thus furnish fitness to be selected, must remember that 

 all science is inadequate to exactly the same degree." 



These sentences seem to imply that the fitnesses or adjustments 

 selected are the outcome of response to a stimulus, and not merely 

 response, but beneficial response, i.e. response in harmony with the 

 environment. We do not know and need not know the why or how 

 of this responsive faculty ; it is to be enough for us that it is a pro- 

 perty of living things. It is not clear how this differs from the 

 following statement by another author : — " All adaptations, at any rate 

 all adjustments concerning whose action and efficacy there is no dispute, 

 have arisen in the same way as the enlargement of a muscle by 

 exercise," i.e. as beneficial response to a stimulus ; and this faculty of 

 response is " a fundamental property of protoplasm " (Cunningham, 

 Nat. Sci. vol. viii. pp. 328 and 330 ; May 1896). But there must be a 

 difference, for these are assertions which Dr. Brooks combats with 

 abundance of sarcasm. 



Perhaps the explanation is that we have here " a bad and unapt 

 formation of words." " Adjustment " seems to be used in two senses : 

 the act of adjusting and the result of adjusting. Just so Professor 

 Brooks sometimes uses " nurture instead of acquired characters" whereas 

 the latter are elsewhere more correctly spoken of as " the effects of 

 nurture " (pp. 55 and 172). Since Dr. Brooks and the Neo-Lamarckian 

 both admit (I believe) the operation of natural selection, the difference 

 between them seems to lie in this : that, according to Dr. Brooks, the 

 faculty of adjusting is a character that varies and is selected and 

 inherited; while, according to the Neo-Lamarckian, the results of 

 adjusting are the characters that are selected and inherited. It is, 

 however, clear that selection can act on the faculty of adjusting, only 

 through its concrete results. Further, no human being can perceive 

 whether the faculty of adjusting is transmitted, except by seeing the 

 results. But in the ovum these results will not be manifest to the 

 most keen-eyed microscopist ; like all other characters, they will appear 



