266 
THE PRINCIPLES OF 
Pari U- 
same results as would follow from an actual inequality 
in the number of the sexes ; for if each male secures- 
two or more females, many males will not be able to 
pair; and the latter assuredly will be the weaker or 
less attractive individuals. Many mammals and sonic 
few birds are polygamous, but with animals belonging to 
the lower classes 1 have found no evidence of this habit. 
The intellectual powers of such animals are, perhaps, 
not sufficient to lead them to collect and guard a harem 
of females. That some relation exists between poly- 
gamy and the development of secondary sexual cha- 
racters, appears nearly certain; and this supports the 
view that a numerical preponderance of males would 
bo eminently favourable to the action of sexual selection- 
Nevertheless many animals, especially birds, which arc 
strictly monogamous, display strongly-marked secondary 
sexual characters ; whilst some few animals, which are 
polygamous, are not thus characterised. 
We will first briefly run through the class of mam- 
ma s, and then turn to birds. The gorilla seems to he 
a polygamist, and the male differs considerably from 
the female ; so it is with some baboons which Jive i* 1 
herds containing twice as many adult females as males, 
n k" outh America the Mycetes caraya presents well" 
marked sexual differences in colour, beard, and vocal 
oigans, and the male generally lives with two or three 
wiies. the male o t the Cebus capucinus differs some- 
what from the female, and appears to be polygamous/ 
Little is known on this head with respect to most other 
monkeys, but some species are strictly monogamous. 
The ruminants are eminently polygamous, and they 
i ", ^ ° n a ’ Silva S e and Wyman, • Boston Journal of Nat. His*-’ 
n ° n Cynocephalus, Brelun, ‘Illust. TMerleben,’ 
‘ 0n M yeetes, Itengger, ‘ Naturgcscli. : Saugethier® 
von Paraguay,’ 1830, s. 14, 20. On Cebus, Brehm, ibid. s. 108. 
