GERMAN PLANKTON INVESTIGATIONS. 



323 



the analyses with the land plants usually used as fodder. 

 The albuminous constituents predominate. Fat is in one 

 case low, in another case abnormally high, and the car- 

 bohydrates are comparatively very low. Other observa- 

 tions are necessary in order to determine whether the 

 vegetable constituents of the plankton, invariably in 

 summer, take a subordinate position as compared with the 

 animals. It is very probable that the smaller chlorophyll- 

 containing Flagellatse, or even Schizophyte algae, pass 

 through the the meshes of the silk bolting cloth No. 20. 

 The Copepoda form a very important food supply for fishes 

 and other plankton-devouring animals. A comparison is 

 instituted between the Copepoda and certain fish and 

 edible Mollusca. The comparison is not so exact as for 

 the plankton and land plants above, because in the case of 

 the Copepoda and the mollusca the carbohydrates must be 

 to some extent contained in the alimentary canal. In 

 other respects, that is for albumen and fat, the Copepoda, 

 oysters and mussels are comparable to the lobster and 

 crab. 



Dry Substance 



Albumen. 



Chitin. 



Fat. 



Carbohy- 

 drates. 



I 

 Ash. 



Herring 



56-42 



— 



35-85 



— 



7-02 





Salmon 



GO -49 







35-62 



— 



3-89 





Flounder 



87-61 



4-38 



— 



8-0 



Cod 



91-08 



— 



1-86 



— 



7-6 







79-80 



— 



10-13 



0-16 



9-41 





Crab 



78-87 



— 



7-69 



3-75 



96 





Plankton 

 Copepoda... 



59 



4-7 



7 



20 



9-3 



Oyster 



46-8 



— 



9-5 



28-1 



16 





Mussel 



54-86 



— 



7-07 



26-0 



12 





