1899] 4 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, ae. 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, 7.¢. as beneficial response to a stimulus; and this faculty of 
response is “a fundamental property of protoplasm” (Cunningham, 
Nat. Ser. vol. vii. 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 
