268 THE PRINCIPLES OF Part II. 



respects, that the males when caught are valued at 

 twenty per cent, above the females. 7 With other pachy- 

 dermatous animals the sexes differ very little or not at 

 all, and they are not, as far as known, polygamists. 

 Hardly a single species amongst the Cheiroptera and 

 Edentata, or in the great Orders of the Rodents and 

 Insectivora, presents well-developed secondary sexual 

 differences ; and I can find no account of any species 

 being polygamous, excepting, perhaps, the common rat, 

 the males of which, as some rat-catchers affirm, live 

 with several females. 



The lion in South Africa, as I hear from Sir Andrew 

 Smith, sometimes lives with a single female, but gene- 

 rally with more than one, and, in one case, was found 

 with as many as five females, so that he is polygamous. 

 He is, as far as I can discover, the sole polygamist in 

 the whole group of the terrestrial Carnivora, and he 

 alone presents well-marked sexual characters. If, how- 

 ever, we turn to the marine Carnivora, the case is widely 

 different ; for many species of seals offer, as we shall 

 hereafter see, extraordinary sexual differences, and they 

 are eminently polygamous. Thus the male sea-ele- 

 phant of the Southern Ocean, always possesses, accord- 

 ing to Peron, several females, and the sea-lion of Forster 

 is said to be surrounded by from twenty to thirty females. 

 In the North, the male sea-bear of Steller is accom- 

 panied by even a greater number of females. 



With respect to birds, many species, the sexes of 

 which differ greatly from each other, are certainly 

 monogamous. In Great Britain we see well-marked 

 sexual differences in, for instance, the wild-duck which 

 pairs with a single female, with the common blackbird, 



' Dr. Campbell, in ' Proc. Zoolog. Soc.' 1869, p. 138. See also an 

 interesting paper, by Lieut. Johnstone, in ' Proc. Asiatic Soc. ofBeDgal,' 

 May, 1868. 



