322 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



Albumen. 



Fat. 



HixiracTis ire 

 from N. 



Cellulose. 



Ash 



Rye Straw 3 - 5 



1-5 



... 38-8 



.. 51-3 .. 



4-7 



Peridineae 13'0 



1-3 



39 



41-5 



5-2 



Good grass hay . . . 13 • 6 



3-2 



.. 48-2 



.. 26-8 .. 



8-2 



On account of their comparatively large amount of 

 albumen, the Peridinese resemble the better kinds of 

 fodder, but their small amount of fat and large amount of 

 cellulose causes them to resemble the poorer sorts. 



As spring approaches, a remarkable change is noticed 

 in the plankton, the percentage of silica becoming very 

 much higher, due to the sudden increase in the Diatoms. 



In order to compare Diatoms with the land plants, the 

 weight, free from ash, must be taken. 



Albumen. Fat. Carbohydrates. 



Very good Lupine ... 29-3 ... 2-8 ... 67-8 



Pea seeds 27-2 ... 2-3 ... 70-4 



Diatoms 28-7 ... 8-0 ... 63-2 



Compared with whole land plants, i.e., excepting 

 special parts such as rape seed, the percentage of fat in 

 Diatoms is invariably found to be much higher. The 

 albumen in Diatoms is also relatively high. On account 

 of the high percentage of fat and albumen, as well as on 

 account of the poverty of the carbohydrates, the Diatoms 

 stand out in marked contrast to most of the land plants. 

 The percentage of albumen in Diatoms is seen to be in 

 excess of that in pea seeds. It must, however, not be 

 forgotten that more than half of the Diatom total weight 

 consists of silica, which possesses absolutely no nourishing 

 properties. Brandt is of opinion that further investiga- 

 tions are necessary to determine the importance of 

 Diatoms as a direct food supply of animals. 



In the summer plankton the animal constituents come 

 into prominence, so that it is no longer possible to compare 



