2G0 THE PRINCIPLES OF [Part II. 



the marine Carnivora, the case is widely different ; for 

 many species of seals offer, as we shall hereafter see,, ex- 

 traordinary sexual differences, and they are eminently 

 polygamous. Thus the male sea-elephant of the Southern 

 Ocean always possesses, according to Peron, several fe- 

 males, and the sea-lion of Forster is said to he surrounded 

 by from twenty to thirty females. In the North, the 

 male sea-bear of Steller is accompanied 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 fe- 

 male, with the common blackbird, and with the bullfinch, 

 which is said to pair for life. So it is, as I am informed 

 by Mr. Wallace, with the Chatterers or Cotingida? of South 

 America, and numerous other birds. In several groups I 

 have not been able to discover whether the species are 

 polygamous or monogamous. Lesson says that birds of 

 paradise, so remarkable for their sexual differences, are 

 polygamous, but Mr. Wallace doubts whether he had suf- 

 ficient evidence. Mr. Salvin informs me that he has been 

 led to believe that humming-birds are polygamous. The 

 male widow-bird, remarkable for his caudal plumes, cer- 

 tainly seems to be a polygamist. 8 I have been assured, by 

 Mr. Jenner Weir and by others, that three starlings not 

 rarely frequent the same nest ; but whether this is a case 

 of polygamy or polyandry has not been ascertained. 



The Gallinacese present almost as strongly-marked 

 sexual differences as birds of paradise or humming-birds, 



8 ' The Ibis,' vol. iii. 1861, p. 133, on the Progne Widow-bird. See 

 also on tbe Vidua axillaris, ibid. vol. ii. 1860, p. 211. On the polygamy 

 of the Capercailzie and Great Bustard, see L. Lloyd, ' Game Birds of 

 Sweden,' 1867, pp. 19, 128. Montagu and Selby speak of the Black 

 Grouse as polygamous, and of the Tted Grouse as monogamous. 



