II2 
NATURE 
[ApRIL 4, 1912 
requires interest, care, and work, and some 
imagination, and not a thing to be undertaken only 
to be done with as soon as possible? 
Would these women who are clamouring for the 
“right ” to do work for which they are obviously 
unfitted turn their superfluous energies to training 
themselves and then training our “‘ Charlottes” in 
the knowledge of the delights of the combination 
of thrift and dainty dishes, of which this book 
gives so fascinating and practical an account, then 
indeed would their now wasted energies have some 
real and useful result. There is no more needed 
reformation than that of work in our kitchens. 
To anyone with a conscience and some little know- 
ledge, the wastes and missed opportunities, even 
in the simplest kitchen, are appalling. 
This book should be a help to many a young 
housekeeper towards bettering things in her own 
home and perhaps inspiring a young “Charlotte ” 
to realise the beauty and importance of her work, 
and to lead her on also to realise the importance 
of small things in the kitchen. 
LELTERS LOY THE EDITOR: 
[The Editor does not hold himself responsible for 
opinions expressed by his correspondents. Neither 
can he undertake to return, or to correspond with 
the writers of, rejected manuscripts intended for 
this or any other part of Nature. 
taken of anonymous communications.] 
Acquired Characters and Stimuli. 
I tHank Sir Ray Lankester for the complimentary 
expression with which he begins his letter (NATURE, 
March 21) and for the friendly feeling which prevents 
him saying I am quibbling. However, he gives his 
reason for thinking I am quibbling. I will admit 
my offence if he will indicate precisely how an inborn 
trait is more inborn and less acquired than an 
acquirement. In my letter I implied that by 
“acquired character” biologists mean a_ trait 
developed under the influence of use or injury. 
Sir Ray Lankester insists that I am wrong. He says 
that Lamarck, the original user, employed the term 
to indicate a trait which is ‘‘abnormal,” because the 
individual who developed it was exposed to an 
“abnormal environment.” To quote his own words, 
“The new character or characters developed in re- 
sponse to the abnormal environment (which we 
assume to be allowed to act on the growing individual 
only, and not on its parents) are called by Lamarck 
—and those who wish to discuss Lamarck’s theory— 
“acquired characters’ (changements acquis). The 
word ‘ acquire’ is used to mean something ‘ added 
to’ or ‘ changed in’ the normal form of the species.” 
He adds ‘That, I take it, is Lamarck’s meaning, 
and it is what I, and others, have for more than 
twenty-five years accepted.” 
I cannot, of course, be sure of the identity of the 
“others? to whom Sir Ray alludes as having taken 
part in ‘‘a historical discussion,” but the following 
passages are taken at random from men who were 
not unknown about that time. ‘Lamarck .. . attri- 
buted the changes of species chiefly to the effects of 
changes in the conditions of life—such as climate, 
food, &c.—and especially to the desires and efforts of 
the animals themselves to improve their condition, 
leading to a modification of form or size in certain 
parts, owing to the well-known physiological law that 
all organs are strengthened by constant use, while 
NO. 2214, VOL. 89] 
No notice is | 
they are weakened or even completely lost by dis- 
use.” * ‘‘It seems difficult and well-nigh impossible 
to deny the transmission of acquired characters when 
we remember the influence which use and disuse 
have exercised upon certain special organs. It is 
well known that Lamarck attempted to explain the 
structure of the organism as almost entirely due to 
this principle alone.”’* ‘And so in the case of other 
animals, Lamarck believed that the adaptation of 
their forms to their habits could be explained by this 
‘simple hypothesis that the habits created the forms, 
through the effects of use and disuse, coupled with 
heredity. Such is what is ordinarily known as 
Lamarck’s theory of evolution. We may as well re- 
member, however, that it really constitutes only one 
part of his theory; for besides the hypothesis of the 
cumulative inheritance of functionally-produced modi- 
fications—to which we may add the inherited effects 
of any direct action exercised by surrounding condi- 
tions of life—Lamarck believed in some transcendental 
principle tending to produce gradual improvement in 
predetermined lines of advance. Therefore it would be 
more correct to designate the former hypothesis by 
the name either of Erasmus Darwin, or, still better, 
of Herbert Spencer. Nevertheless, in order to avoid 
confusion, I will follow established custom, and sub- 
sequently speak of this hypothesis as the Lamarckian 
hypothesis-—understanding, however, that in employ- 
ing this designation I am not referring to any part or 
factor of Lamarck’s general theory of evolution other 
than the one which has just been described—namely, 
the hypothesis of the cumulative transmission of 
functionally-produced or otherwise ‘ acquired modifica- 
tions.’ ’’* 
It will be seen that I have sinned, if I have sinned, 
in good company. The men from whom I quote evi- 
dently regarded an acquired character as, in essence, a 
“functional modification,’”” an effect of ‘‘use or dis- 
use,’’ ‘‘to which may be added the inherited effects of 
any direct action exercised by surrounding conditions 
of life’ (e.g. injury). I suppose I could cite scores 
or hundreds of similar passages. The fundamental 
errors expressed or implied in them all are (1) that 
there is a general law that all organs are strengthened 
by constant use and weakened by disuse, and (2) that 
use and disuse produce only ‘‘abnormal”’ traits. 
There is no such law; some structures (e.g. external 
ears, hair, teeth) in the higher animals ce man) 
are not in the least affected by use; there is no clear 
evidence that animals low in the scale of life develop 
at all under this influence; and very clear evidence 
that the power, the potentiality, of so developing has 
undergone such increase in the higher animals that 
it constitutes the main feature of their evolution. To it 
they owe all their physical and mental adaptability— 
their intelligence, for instance. The child grows into 
the adult just as much under its influence as the 
adult grows into the exceptional adult (e.g. the trained 
athlete). We have every reason, therefore, to believe 
that the potentiality to develop under the influence of 
use, at any rate to any considerable extent, is a late 
and a high product of evolution. The point 
raised by Sir Ray Lankester is, however, as 
far as JI am concerned, immaterial—a distinction 
without a difference. If he prefers, let us, by 
all means, consider abnormality resulting from 
abnormal use as the distinguishing characteristic of 
an acquirement. To take an illustration, the muscu- 
lar development, both of the ordinary individual and 
of the blacksmith, is due to use. Sir Ray Lankester 
regards the former as normai, and therefore inborn 
1 Wallace, ‘‘ Darwinism,” p. 3. 
2 “ Weismann on Heredity,” English translation, 2nd edition, vol. i., 
BPS Saas = Pech f 
* Romanes, ‘‘ Darwin and After Darwin,” vol. i., p. 255. 
