170 



TELEOSTOAIES 



ber, and from its peculiar life habit retains permanently 

 a number of its embryonic characters ; it has thus its 

 elongated larval form, a functional pronephros, a noto- 

 chordal skeleton and immature fin conditions (Emery, 

 Ref. p. 249). 



To what degree the structures of fishes may be varied 

 by artificial selection is an interesting question, but one 

 that has as yet received little attention even from those 

 who have made artificialization an especial study. In the 

 instance of the GoldjisJi it is well known how wide a 



Fig. 176. — Goldfish, Carassius aurahts ("Telescope" variety). X I. (After 

 GiJNTHER.) Japan. 



variation has been produced in colour, size, and proportions. 

 Fin structures are elaborately developed, long, drooping, 

 lace-like, often to a degree which must render progression 

 both slow and difficult. Even the eyes have been made 

 to become large and protruding (Telescope-fish, Fig. 176). 

 In carp the variation in scale character, due to artificializa- 

 tion, is also to be mentioned. It is natural, perhaps, that 

 artificial selection has been most successfully practised 



