THE SEXES, AND CRITICISM 0¥ SEXUAL SELECTION. 3 1 



SUMMARY. 



1-3. A broader basis must be sought from which to understand the 

 differences between the sexes. A general survey shows, that the males are 

 more active in habit, the females more passive ; that the males tend to be 

 smaller and to have a higher body-temperature, while the females tend to 

 be larger and to live longer. 



4. The close association of secondary sexual characters with the 

 reproductive function, is shown in the period or in the periodicity of their 

 development, in the effects of castration, in the peculiarities of aged 

 females, &c. Richer pigmentation, and other male characteristics, are to 

 be interpreted as expressions of the katabolic predominance in the con- 

 stitution of males, as opposed to the anabolic preponderance of the 

 females. 



5. Sexual selection, as an explanation of secondary sexual characters, 

 is limited, by being teleological rather than setiological, does not account 

 for origins nor incipient stages, postulates subtle aesthetic sensitiveness, and 

 is beset by numerous minor difficulties. Yet the opposed positions of 

 Darwin and Wallace both emphasise indubitable facts ; while the criticisms 

 of Mivart, the theory of Brooks, and the suggestions of Rolph, Mantegazza, 

 and others, lead on towards a deeper analysis. The general conclusion 

 reached, recognises sexual selection (so far with Darwin) as a minor 

 accelerant, natural selection (so far with Wallace) as a retarding "brake," 

 on the differentiation of sexual characters, which essentially find a con- 

 stitutional or organismal origin in the katabolic or anabolic diathesis 

 which preponderates in males and females respectively. 



LITERATURE. 



Brooks, Darwin, Mivart, Wallace. — As before. 



EiMER, G. H. T. — Die Enstehung der Arten auf Grund von Vererben 

 erworbener Eigenschaften, nach den Gesetzen organischen Wachsens. 

 Jena, 1888. 



Geddes, p. — Articles Reproduction, Sex, Variation and Selection. 

 Encycl. Brit. Also on the Theory of Growth, Reproduction, Sex, 

 and Heredity. Proc. Roy. Soc. Edin. 1885-6. 



RoLPH, W. H. — Biologische Probleme. Leipzig, 1884. 



Weismann, a. — Studies in the Theory of Descent (Meldola's Transla- 

 tion). London, 1880-82. 



Wallace, A. R. — Darwinism. London, 1889. 



