340 SEXUAL SELECTION. Part II. 



can I find any well-marked instances of sexual dif- 

 ferences such as more particularly concern us. In 

 Glomeris limbata, however, and perhaps in some few 

 other species, the males differ slightly in colour from 

 the females; but this Glomeris is a highly variable 

 species. In the males of the Diplopoda, the legs be- 

 longing to one of the anterior segments of the body, or 

 to the posterior segment, are modified into prehensile 

 hooks which serve to secure the female. In some 

 species of lulus the tarsi of the male are furnished 

 with membranous suckers for the same purpose. It is 

 a much more unusual circumstance, as we shall see 

 when w^e treat of Insects, that it is the female in 

 Lithobius which is furnished with prehensile appen- 

 dages at the extremity of the body for holding the 

 male. 17 



17 Walckenaer et P. Gervais. 'Hist. Nat. cles Insectes : Apteres,' 

 torn. iv. 1847, p. 17, 19, 68. 



