102 The Field Naturalisfs Qua7'terly May 



strong for our theories, and we shall find, on honest examin- 

 ation of the evidence for and against, that some of the 

 "demersal" {i.e., heavy) eggs are laid almost above low- 

 water mark, while others are deposited some miles from dry 

 land. Nor is it possible to find any constant relation 

 between the migratory fishes and those which deposit these 

 same heavy eggs. It was formerly argued — ingeniously, but 

 on insufficient evidence, as later research soon showed — that 

 the fishes hatched from heavy eggs were more migratory 

 than those hatched from floating eggs, since much of the 

 necessary dispersal of the species was already accomplished 

 in the latter case by the drifting &^g itself. This argument 

 was invariably illustrated by the case of the migratory her- 

 ring and its demersal o.^'^. On the other hand, it was 

 afterwards discovered that the mackerel, fully as restless a 

 wanderer as the herring, came from a floating &gg. It is not 

 therefore surprising to find that the mackerel has a much 

 wider distribution than the herring, the former being more 

 or less confined to the cold and cool seas of the northern 

 hemisphere, the mackerel ranging into warm seas as well. 

 In conclusion, a word of caution must be added in respect 

 of the commonly accepted theory of a general spring migra- 

 tion among our sea-fish of all kinds. Within certain limits 

 this is no doubt the case. At the same time, the warming 

 of the sea close to our coasts is the sign for renewed activity 

 not alone among the fish themselves, but also among the 

 smaller longshore fishermen, the very class from which in- 

 quirers would be more likely to draw their information than 

 from the less accessible deep-sea trawlers or liners. There 

 is thus the risk of confusing with the genuine migrations of 

 the mackerel and pilchards and whiting a series of smaller 

 movements among the flat - fish and pout, which consist 

 rather in once again showing an interest in the baits offered 

 them. One more genuine migrant occurs to mind, and that 

 is the bass. During the middle of April, and more con- 

 spicuously in the early days of May, the shoals of bass once 

 again make their appearance in the Exe and Teign and 

 other south-coast rivers, and once again, in early autumn, 

 they will disappear as regularly and as completely as the 

 swallows. We know where the swallows go, but the 



