272 
THE PEINCIPLES OF 
Part II. 
from each other in external appearance, it is the male 
which, with rare exceptions, has been chiefly modified ; 
for the female still remains more like the young of her 
own species, and more like the other members of the 
same group. The cause of this seems to lie in the 
males of almost all animals having stronger passions 
than the females. Hence it is the males that fight 
together and sedulously display their charms before 
the females ; and those which are victorious transmit 
their superiority to their male offspring. Why tire 
males do not transmit their characters to both sexes 
will hereafter be considered. That the males of all 
mammals eagerly pursue the females is notorious to 
every one. So it is with birds ; but many male birds 
do not so much pursue the female, as display their 
plumage, perform strange antics, and pour forth their 
song, in her presence. With the few fish which have 
been observed, the male seems much more eager than 
the female ; and so it is with alligators, and apparently 
with Batrachians. Throughout the enormous class of 
insects, as Kirby remarks , 11 “ the law is, that the male 
“ shall seek the female.” With spiders and crustaceans, 
as I hear from two great authorities, Mr. Black w T all and 
Mr. C. Spence Bate, the males are more active and more 
erratic in their habits than the females. With insects and 
crustaceans, when the organs of sense or locomotion are 
present in the one sex and absent in the other, or when, 
as is frequently the case, they are more highly developed 
in the one than the other, it is almost invariably the male, 
as far as I can discover, which retains such organs, or has 
them most developed ; and this shews that the male is 
the more active member in the courtship of the sexes . 12 
11 Kirby and Spence, 1 Introduction to Entomology,’ vol. iii. 1826, 
p. 342. 
12 One parasitic Hymenopterous insect (Westwood, 1 Modern Class, 
of Insects/ vol. ii. p. 160) forms an exception to the rule, as the male 
