SEA-FISHERIES LABORATORY. 



329 



If, now, we take the very different and possibly 

 exceptional monthly distribution of sunshine in '07, and 

 represent it as a curve (fig. 15) along with the curve of 

 the monthly plankton of that year, we get the curious 

 result of four sunshine elevations in March, May, July 

 and September, and four plankton elevations in April, 

 June, August and October. It is true that the highest 

 sunshine peak is in July, and the highest plankton peak 

 in April, but that difference in degree may be due to the 



1>« 08 '00, 



action of other factors, such as periodicity in life-histories 

 and succession of species throughout the year; and after 

 noting all differences, the curious correspondence between 

 these two curves for '07 is remarkable, and it is the more 

 striking when we remember that in the two years since 

 ('08 and '09, fig. 14), when the distribution of sunshine 

 showed a marked maximum in May, the plankton 



