D.— ZOOLOGY 



91 



of food for the larvae ; if that is so the herring has failed in exactly the 

 same way as the other fish whose larvae Mr. Russell has studied. There 

 are, however, reasons for believing that this may not be the correct explana- 

 tion, for the herring spawn in winter and thus diflfer strikingly from the 

 majority of fish we have been considering. They are evidently able to 

 find sufficient food at a time when the plankton is at a minimum and they 

 are not dependent on the rich zooplankton which follows the spring 

 outburst of phytoplankton. It is perhaps more probable that the earlier 

 year classes of herring have responded to the abnormal conditions in the 

 Channel by forsaking their usual line of migration, and that they now go 

 to other spawning grounds. 



Table II. 



Renewal of the phosphate in the Channel appears to be largely depend- 

 ent on an inflow of mixed Atlantic water, which is rich in phosphate 

 because it contains water that has upwelled at the edge of the continental 



« For further particulars see L. H. N. Cooper : ' Phosphate in the EngHsh 

 Channel, 1933-38, with a comparison with earlier years,' Journ. Marine Biol. 

 Assoc, XXIII, 1938 (in press). 



' The numbers of young fish caught in half-hour oblique hauls of the standard 

 2-metre net, expressed as the sums of the monthly average catches. Hauls were 

 made weekly, so far as possible, the number varying from 42 to 52 per annum. 

 [Data by F. S. Russell, published in part in Conseil Internal. Mer, Rapp. et Proc- 

 Verb. des Riunions, C, part 3, p. 9 (1936)]. 



« The total number in the standard hauls referred to above. Data by F. S. 

 Russell. 



