FISHES 



199 



directed to the fertilisation of the eggs, and not to the subse- 

 quent protection of them by the male. It might be asked, if 

 the views maintained by me are correct, why have not the 

 actions of the male Cantharus produced corresponding struc- 

 tural modifications similar to those described below in Cal- 

 lionymus lyra. In reply to this, it may be pointed out that 

 the male Cantharus is not stated to perform such definite 

 and vigorous gestures of courtship as the Callionymus. The 

 change of colour which takes place in the former is to be 

 attributed, as in the latter, to the increased production of 

 pigment in the skin under the influence of the nervous 

 excitement associated with the sexual instinct. 



Scorpamidm-Sebastes norvegicus, sometimes known as the 

 Norway Haddock, is a strongly spined species belonging to the 

 Scorpaenida?. Specimens have occasionally been taken on the 

 east coasts of Scotland and England. This species is vivi- 

 parous, the female producing about a thousand living young. 

 Fertilisation must consequently be internal, but no secondary 

 sexual differences appear to have been described, nor has the 

 process of fertilisation been observed. This case appears, 

 therefore, to be an illustration of the fact, sufficiently obvious 

 in many mammals and birds, that internal fertilisation does 

 not necessarily involve sexual dimorphism. 



Gobiidce. The Dragonet, Callionymus lyra, is usually placed 

 in the family Gobiidre. The fact that it has pelagic ova, while 

 those of the species of Gdbius are adhesive, is in itself no 

 objection to this classification ; as in other families, e.g. 

 ClupeidaB, some species have adhesive ova and others pelagic. 

 The adult male dragonet differs so much in appearance from 

 the adult female that it was at one time described as a dis- 

 tinct species, under the name C. lyra, the female being named 

 C. dracunculus. The peculiarities of the male consist chiefly 

 in its vivid colouring and the great elongation of the first 

 dorsal fin. The second dorsal and the ventral (anal) fins are 



