236 Heredity. 



I will now give a few of those which seem to me to be 

 most opposed to my general conclusion. 



j^^emale Modification, 



In certain sjoecies of the amphipod crustacean genus 

 Melita, the females differ from all other amphipods by 

 having the sexual lamellae of the joenultimate pair of 

 feet produced into hook-like processes, of which the 

 males lay hold with the hands of the first pair. In an- 

 otlier amphipod, BrachysceluSj the male possesses, like 

 all other ampi^ipods, a pair of posterior antennas, but 

 they are absent in the female, so that the latter differs 

 more than the male from allied forms. Darwin states 

 that the females of certain water-beetles, as Dijtiscus 

 Acilius and IIf/dropo7nts, have their wing-covers grooved 

 or thickly set with hairs or punctured, in order to ena- 

 ble the male to cling to the slippery surface of their hard 

 and polished bodies. 



The call duck is a domesticated breed which receives 

 its name from its extraordinary and exceptional loquaci- 

 ty, and as this loquacity is confined to the female, while 

 the male hisses like other ducks, we must regard this as 

 a case of female modification. We know f I'om the state- 

 ments of Blumenbach and Bechstein that, previously to 

 the year 1813, the great bony protuberances on the skuH 

 which characterize the Polish breed of fowls, were con- 

 fined to the females, although they are now equally de- 

 veloped in both sexes. There can be no doubt that this 

 peculiarity originated in the females, and was subse- 

 quently inherited by the males. 



Among the Phasmidae or spectre insects the females 

 alone, in some species, show a most striking resem- 

 blance to leaves, while the males show only a rade ap- 

 proximation, and Darwin has pointed out that, as we can 



