DECEMBER 24, 1897. ] 
The lower vertebrata do not tend their 
young, which, therefore, are hatched highly 
endowed with instinct, but with little power 
of acquiring mental characters. Reptiles, 
having better developed brains, have greater 
capacities for acquirement than fish ; they 
ean be trained to a much great extent, can 
learn much more, and have been known to 
manifest affection for their masters, in which 
eases the acquired affection has been so 
strong as to overcome the instinctive dis- 
like. Birds and mammals, like ants, tend 
their young, which, in proportion to the 
amount of protection accorded, are born 
helpless and devoid of instinct, but capable 
of mental acquirement. Ever, as we rise 
upwards in the scale, do we find this in- 
creasing protection associated with a grow- 
ing helplessness at birth, and a steadily en- 
larging capacity for acquirement which finds 
physical expression in a more and more 
developed brain, especially of the cerebral 
portion of it. A partridge at hatching and 
a fawn at birth are able to codrdinate their 
muscles to a considerable extent, and have 
many other instincts. The parrot and the 
pup are very much more helpless, but their 
capacity for acquirement is greater in pro- 
portion. Highest of all, the human infant 
is born absolutely helpless; it is unable to 
coordinate all but a very few groups of 
muscles; its instincts are reduced to a 
minimum ; it cannot even seek the breast ; 
but it is protected with prolonged and ten- 
der care, under which its vast powers of ac- 
quirement come into play. 
Instincts, therefore, have undergone great 
retrogression in the higher types, but amid 
this general retrogression three instincts at 
least have undergone evolution: (1) the 
parental instinct to protect the offspring ; 
(2) the parental instinct to impart to the 
offspring the acquired knowledge which 
subserved the parents’ survival; and (3) 
the instinct which impels the offspring to 
imitate the parent, and so acquire the phys- 
SCIENCE. 
941 
ical and the mental traits, the traditional 
knowledge and ways of thinking and acting, 
which the latter acquired. This subject is 
a very interesting one, but my space is 
limited, and therefore I will not dilate on 
it, but content myself by instancing such 
familiar examples as the hen, the cat and 
the human being in proof of my statements. 
Each of these animals teaches its young in a 
different way, and the instinct of the young 
causes it to imitate the parent and sport in 
such a manner as to develop (1%. e., favor the 
acquirement of) the physical and mental 
characters which conduce to the survival 
of the individual and the race. If it be 
doubted that animals lower than man have 
traditional knowledge, which is handed 
from generation to generation, I have only 
to instance parrots of New Zealand, which 
have recently acquired the habit of sheep 
eating, and the change which soon occurs 
in the demeanor of the higher animals to- 
wards man when he first enters a land 
where he was previously unknown, e. g., 
the Galapagos Islands. In such lands lower 
animals (insects, for instance), if they ex- 
hibit alarm on his first appearance, show 
no increase of it in subsequent generations. 
Some of this traditional knowledge, es- 
pecially when it is of a kind greatly to favor 
survival, is doubtless of vast antiquity. Of 
such a nature, if I am right in regarding it 
as an acquirement, must be the slave-making 
habit of certain ants, since their very phys- 
ical structure has been immensely modified — 
by it—not by the congenital transmission of 
acquired characters, but wholly by the 
transmission and accumulation of such 
inborn variations as best served the utili- 
zation of the acquired character ; hence, for 
instance, the great jaws of F. rufescens. 
In man occur many examples of physical 
structures modified by the persistent ac- 
quirement, in generation after generation 
during long ages, of particular acquired 
characters. For example, his whole di- 
