46 SALT-WATER FISHES 



by Dr. Fulton, and taken over a wider area comprising 

 very different localities, there can be any advantage in 

 making deductions from the available data. 



The unaided spawning of fishes in captivity is always 

 interesting, particularly where a valuable food-fish is concerned. 

 The common sole, for instance, spawned in the tanks of the 

 Marine Biological Association at Plymouth for the first time 

 in the year 1895, nor, up to the time of writing, have brill and 

 turbot naturally spawned in tanks. The eggs of the one have, 

 it is true, been artificially fertilised with the milt of the other, 

 but that is quite a different matter. The first to achieve this 

 was Mr. Scott, of the Scotch Fishery Board, and the episode 

 is fully described by Mcintosh and Masterman.* This 

 suggests a few remarks on the subject of hybrids generally. 



The fishermen have somewhat remarkable notions on the 

 subject of hybridisation in fishes. The Little Ling {Molva 

 abyssorum), for instance, known to Norwegians. as the " birke- 

 lange," they regard, of course erroneously, as a cross between 

 the ling (Molva) and hake {Merluccius). Even scientific 

 writers differ in their view of hybrids, and examples which 

 Day considered to be hybrids between, for example, the herring 

 and pilchard have been regarded by Bateson f as mere varieties 

 with scales abnormal in both size and number, and rather more 

 gill-rakers than in the type forms, or those forms from which 

 the types were severally described. 



In the flat-fish {^Heterosomatd) real or alleged hybrids are not 

 uncommon. The egg of the brill has been artificially fertilised 

 with the milt of the turbot and also with that of the dab, and 

 what is done in the laboratory may possibly be done also in 

 nature. The Grimsby fishermen, for instance, often catch a 

 peculiar-looking flat-fish, which they firmly believe to be a 

 hybrid between the brill and turbot, and so high an authority 

 as Mr. Holt is inclined to agree with them, having found that 



* op. cit, p. 338. 



t See Froc. Zool. Soc, 1890, p. 586, and 1894, p. 164. 



