3o8 THE COURTSHIP OF ANIMALS 



when adult life is attained female glands appear and 

 hermaphroditism is established. Such hermaphrodites 

 have the singular distinction of being males which have 

 acquired female attributes, true females being unknown 

 among them ! 



In one of the parasitic Crustacea (Chondr acanthus) 

 infesting the gills of Gurnard, Plaice, Skate and other 

 fish, the adult female is about half an inch long, and 

 very unlike a Crustacean in appearance ; the male is 

 an extremely minute maggot-like object — a few milli- 

 metres in length — and lives permanently attached to 

 the belly of his mate just at the base of the tgg masses. 

 More remarkable still is the case of another nearly related 

 parasitic species — Lernea — which becomes sexually mature 

 in its childhood. The males perform their part and die; 

 their mates arrive at maturity and settle down to a 

 comfortable life as parasites on fish, reproducing without 

 further mating. 



That Parthenogenesis and Hermaphroditism are but 

 specialized forms of reproduction, leading sooner or later 

 to degeneration and extinction, there can be no doubt. 

 They are, so to speak, failures in the evolution of sex, 

 demonstrating in a very forcible fashion the impossibility 

 of progress — as we understand it — where the sexual 

 functions are thus combined. 



To the differentiation of sex, resulting in separate male 

 and female individuals, we must attribute the marvellous 

 complexity of the pageant of life which confronts us 

 to-day. The story of the Courtship of Animals is only 

 one of an infinite number of incidents in this pageant, 

 and one which is by no means easy of interpretation. 



In these pages an attempt has been made to show that 

 this differentiation of sex has, throughout, been accom- 



