400 G. E. BULLEN. 



pilchard drift-fishermen at Newlyn, Mevagissey and elsewhere contend 

 that good catches are seldom made in water which " brimes " consider- 

 ably. On one occasion at Mevagissey an old fisherman, on seeing 

 several Hormi'phora jAumosa drop from the first net of a fleet shot for 

 pilchard, informed the writer that he knew that there would be a poor 

 catch, which subsequently proved to be the case. The explanation, 

 however, which was given, was to the effect that these ctenophores, 

 becoming caught up on the meshes, rendered the nets conspicuous by 

 their phosphorescence. 



It may be mentioned, moreover, that boats fishing further out to sea 

 made fair catches, and it is possible that these ctenophores occurred 

 abundantly, as is often the case, in the estuarine water flowing out of 

 the harbour, and in the fairly still water in the immediate vicinity. 



The above statements constitute our sole direct evidence of the 

 extent to which the theory of selective feeding in mackerel and certain 

 other drift fishes can be carried. We may therefore summarize 

 some other points which may lend further support to the suggestion. 



There is a fair amount of evidence to show that mackerel, herring, 

 and pilchard are continually in a state of voluntary movement when 

 engaged upon inshore migration. 



With mackerel, the opinion is generally held by fishermen that once 

 fish are known to be congregated in certain areas, unproductive fishing 

 is due to the fact that the fish are not at the surface. The continued 

 prevalence of N. and IST.W. gales is well known to have a marked effect 

 upon the western fishery, even at its height. The slight knowledge 

 which we now possess respecting this fish's winter habitat* would 

 strengthen the idea that it would naturally seek deeper layers of water, 

 when the surface was subject to inclement conditions of atmosphere. 



Mr. Cowley's statement, already cited, that mackerel and herring 

 kept in captivity are continually in motion night and day, is quite in 

 accordance with the views held by several intelligent fishermen, 

 questioned on the subject by the present writer. 



Moreover, the bare fact of the gradual progression shoreward of 

 mackerel spread over a wide area at tlie beginning of the fishing 

 season, resulting in a concentration of many thousands of shoals 

 within the comparatively limited area afforded by the most productive 

 fishing waters of May — i.e. within a 50-mile radius to the S. and S.W. of 

 Scilly — would, to a great extent, preclude the suggestion that the fish are 

 much affected in their inshore movements by the influence of currents. 



* Vide A. Cligny, ^^ Les prctendus migrations du maqncrmu." Anu. Sta. Aquicole, 

 Boulogne-sur-mer, Nouv. Ser., Vol. I, 1905. 



