172 University of California Publications in Zoology [Vol. 16 



but lie does not tell how the filtering is accomplished or what organs 

 take part. 



The method of food-getting by the Ostraeoda appears to have re- 

 ceived more attention, and since it is similar to that in the copepods, 

 it may be well to make note of it here. Biedermann (1911, p. 651) 

 gives this account for the Daphnids : 



Die betreffenden Kbrperchen werden durch Bewegungen der Beinanhange 

 herbeigestrudelt und schlieslich zu einem Bissen geformt, der dann durch peri- 

 staltische Beweguugen des Oesophagus rasch in den Mitteldarm befordert wird. 

 Mittels der reusenartigeu Fortsatze ihrer bestandig auf und ab bewegten 

 Gliedmassen vermogen die Daphnien grosse Wassermengen diirchzuseihen. 



Woltereck (1908, p. 872) makes very similar statements. 



I can state, from observations upon Calanus finmarcMcus and 

 Eucalanus elongatus, that the copepods get their food in essentially 

 the same manner as the ostracods. I have watched many living speci- 

 mens of Calanus get carmine grains in what appears to be necessarily 

 the method by which they obtain organisms for food from the sea 

 water. 



"When a living Calanus is put into a small amount of water, the 

 animal nearly always scurries about, ventral side up. Under these 

 conditions it is possible to see how solid particles are concentrated and 

 taken into the mouth. The necessary preliminary to actual ingestion 

 is the production of currents which transport the particles toward the 

 bodj''. The movement of the water is due to the activity of the ap- 

 pendages, chiefly those of the head. It is not possible to state just how 

 the currents are set up, because of the great rapidity with which the 

 appendages move. It is easy to determine that the bits of carmine are 

 brought from considerable distances toward the body ; they come from 

 in front of the animal and pass between the bases of the anterior 

 antennae, or from behind the bases of the posterior maxillipeds. In 

 botli cases the particles are driven toward the mouth. At times, how- 

 ever, the carmine is driven in all directions from the body, but one 

 cannot see how this is brought about. 



While some of the appendages play an active part in the process of 

 food-getting, others with their bristles assume a passive but important 

 role. This consists in directing the moving particles definitely toward 

 the mouth, and it is brought about chiefly by the long spinose bristles 

 of the anterior maxillipeds. As indicated in figure 1, they are so 

 arranged that those of each appendage form the side of a trough or 

 funnel which narrows at the anterior end. The long bristles do not 



