316 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



Allen and Mr. Gr. E. Bullen did some interesting work, 

 at the Plymouth Marine Laboratory, demonstrating the 

 connection between mackerel and Calanus and sunshine in 

 the English Channel. 



In an earlier part of the present volume, Mr. A. Scott 

 has recorded that at the very time we were finding the 

 mackerel feeding on Calanus in the Hebrides, he found 

 them gorging on Pleurobrachia in the Irish Sea. 



The fact is that although a fish like the mackerel or 

 herring may have a normal or favourite food, it may on 

 occasions be found associated with and devouring almost 

 any larger form of the zoo-plankton which is locally 

 abundant. If, as Putter contends, the normal, generally 

 distributed plankton of the sea, is not sufficient in amount 

 to nourish a fish swimming through it haphazard, and 

 taking what it can get from the water passing through its 

 mouth, it becomes the more necessary for fish such as 

 shoals of mackerel and herring to seek out and follow 

 abnormal tracts of especially abundant and nourishing 

 plankton, so as to appear in a locality where Calanus, for 

 example, is swarming, and to migrate elsewhere when the 

 Copepoda disappear — in a word, to hunt their food in place 

 of absorbing it. These considerations give, of course, an 

 entirely new importance to that irregular distribution of 

 the plankton which is so marked a character of our coastal 

 waters. 



The only other organism that need be mentioned is 

 the Pteropod Limacina retroversa. This first appeared in 

 a gathering off Ardnamurchan on July 14th, and after 

 that was found in most of the hauls taken in open water, 

 such as the west coast of Mull, off Staffa, at Tiree, off 

 Hyskeir, off the West of Skye, at the Shiant Isles, and 

 elsewhere; but none were found up the Lochs or in the 

 more sheltered localities. It was frequently present in 



