232 The Ottawa Naturalist. | March 



integument of the skin by lying- over them, and then carry them 

 about until hatched. 



But in most fishes which take care of their young- the filial 

 duties, strange to say, devolve upon the males. A very singular 

 instance of this is some of the Pipe-fishes, upon the males of which 

 devolves the duty of caring for the young. On the ventral side o^ 

 the male is a long groove : the opening of a pouch which is 

 suspended from the fish, and in which the eggs and hatched-out 

 young ones are carried about ; whereas the female does not 

 possess any such pouch, and after depositing the eggs she takes 

 no further care of them. 



Again, the male Stickleback constructs a little nest of weeds 

 or other material, which has an entrance at one side. According 

 to Costa, who made a close study of the habits of sticklebacks, 

 and upon whose observations these remarks are in measure based, 

 he then goes in search of a female, whom he conducts to the nest 

 where she lays some eggs. Then she makes her exit by the 

 opposite side of the nest, so that it now has two openings. Next 

 day or so he goes again in search of a female finding perhaps, the 

 same one, or perhaps another, who a second time is escorted to 

 tha nest ; and each day this is repeated until the nest contains a 

 goodly number of eggs. Then he assiduously guards them from 

 intruders, including the very female sticklebacks. Nor do his 

 duties cease until the eggs are hatched and the young are able to 

 look out for themselves. 



The males of the cat-fishes of the genus Arius have another 

 way of taking care of the eggs. The eggs of these fishes are pro- 

 portionately very large, so that the females lay only a compara- 

 tively few. These the male of some, if not all, of the species, 

 carries about in his mouth, or rather in his capacious pharynx ; 

 until hatched. 



How the Knottv Question as to the Propagation of the Eel 



was Solved. 



Since Aristotle's time the mode of propagation of the eel has 

 been one of the most knotty questions which has engaged the 

 attention of ichthyologists Aristotle himself qfave the subject con 



