378 MONTGOMERY — MORPHOLOGICAL SUPERIORITY. [Oct. 7. 



The other characters in which the males of Vertebrates differ 

 from the females are secondary sexual. Sometimes such external 

 differences are very slight or not perceptible, as in many of the 

 Fishes, Birds and urodelous Batrachia. In most of the group, as we 

 found for the Invertebrates also, the male is smaller ; this is the 

 case in the Acrania, Cyclostojnafa, Selachii^ most TeUostomi^ 

 Dipnoi, most Batrachia, even in most Reptilia. In most Birds 

 where there are sexual differences in size the male is the larger 

 (but the female is in certain species of Falconidce and Scolopacidce), 

 and in Mammals too the male is generally larger. This is an 

 important difference, particularly when it implies a longer growth 

 period and slower attainment of maturity, as in the Primates; we 

 shall recur to this point. When there occurs dichromatism, it is 

 the male that has the brighter or the more contrasted colors, as it 

 s the male that possesses more marked integumentary structures, 

 such as odoriferous glands, combs, plumes, greater development of 

 feathers and hair, spurs, etc. But the greater intensity of colora- 

 tion does not always denote morphological advance, for frequently 

 the colors are not structural (diffractive) ones. And the greater 

 complexity or size of integumentary structures is well known to be 

 a character of little morphological importance, because of the lack 

 of conservatism of such parts, their ready susceptibility to change. 

 Among closely related forms, as in some families of Birds, we may 

 find a species in which the sexes are externally alike in color and 

 plumage, and another species in which they are quite dissimilar in 

 these respects. In the Reindeer the cow has antlers as well as the 

 bull, contrary to the condition in other deer. It is only rarely that 

 the differences of the male are of greater morphological import, as 

 in the different form of skull in the male salmon. We may decide 

 from another point of view that secondary sexual characters must be 

 estimated as of little value, because they have not even the worth 

 of a species diagnostic, being not representative of all the individ- 

 uals of a species. Accordingly, such secondary sexual differences 

 are of too small worth to occupy much attention in the matter of 

 comparing the sexes. 



We have now briefly compared the sexes by the standards of the 

 structure of the reproductive organs and of the secondary sexual 

 differences. We have found that while the female usually shows 

 more advancement in the reproductive organs, the male evinces 

 more in secondary sexual characters. Obviously it becomes a 

 question of which of these characters is the more important. 



