GENERAL BIOLOGY 



721 



of the catches. If we compare such catches at different depths 

 and in different waters, we generally get a fair idea of the relative 

 amount of nourishment present, and it may be of interest to 

 examine some catches of this kind from the Atlantic and the 



Fig, 514. 



Chiasmodus ?iiger, Johns. Nat. size, 9.5 cm. From Station 52. 



Norwegian Sea, where the " Michael Sars " employed the same 

 silk hoop-nets, i metre in diameter, with J millimetre mesh. 

 To commence with, we will consider the same hauls from the 



*> 



Fig. 515. 



Chiasmodus niger, Johns. This specimen had swallowed a larger specimen of the same species. 



Nat. size, 5.7 cm. From Station 56. 



Atlantic which in Chapter IX. we have discussed from a 

 systematic point of view, noting the volume of small pelagic 

 animals captured, compared with the temperature, specific 

 gravity, and viscosity of the water at corresponding depths. 



