SEA-FISHERIES LABORATORY. 367 



sunshine also give a high record for the same month, as 

 the following table shows : — 



August. Temp. Sun. Rain. 



Oban S'way Oban S'way Oban S'way 



1911 ... 60-8 57-4 199 166 4-61 3-92 



1912 ... 54-0 51-2 70 99 3-81 5'59 



If, then, temperature and the amount of sunshine 

 during the month have any effect upon the amount and 

 distribution of the plankton, here is a case where one 

 would expect the effect to be well-marked. 



The right columns of the list on p. 348 show that 

 (after removing all those localities that were sampled for 

 the first time in 1912) most of the remainder showed the 

 same type of haul in 1912 that we recorded in 1911. A 

 few, however, in the Firth of Lorn and on the north 

 coast of Mull have lost their phyto-planktonic and neritic 

 character, and must now be classed as oceanic zoo- 

 plankton. But, on the other hand, the hauls taken off 

 Colonsay, off Ardtornish in the Sound of Mull, and at 

 the mouth of Loch Seaforth, along with some of the 

 gatherings taken far up the lochs, such as those in Loch 

 Swen, in Loch Seaforth and in Upper Loch Torridon, 

 show phyto-plankton mainly of a neritic character. It 

 is possible that the effect, if any, of the great heat and 

 unusual amount of sunshine in August, 1911, was not 

 shown by the plankton until later. 



We showed last year* that in the Irish Sea a 

 marked increase in the plankton in September and 

 October, amounting to about nine times as much as in 

 the same period of the previous year, seemed to 

 correspond with the larger amount of sunshine in 

 August, 1911 (194 hours recorded at Port Erin, as 



* Lancashire Sea Fisheries Report for 1911, p. 153. 



