THE PHOTIC REACTIONS OF SARCOPHAGID FLIES 



175 



TABLE 1 



Showing the duration of life of (a) Lucilia caesar and (b) Calliphora vomitoria 



A lake beach, such as that of Lake Erie at Cedar Point with its 

 quantity of dead fish cast up at fairly regular intervals throughout 

 the entire summer, affords a rare opportunity for the study of 

 sarcophagid fly-larvae in their aggregated reactions, and the ease 

 with which the animals can be reared in the laboratory under 

 practically normal conditions is also favorable for study. A com- 

 bination of field and laboratory observation affords in the writer's 

 estimation, the most satisfactory basis for experimental work. 

 The normal environment and normal behavior of the organism 

 should have the experimenter's closest attention, in order to aid 

 in the correct interpretation of the phenomena observed under 

 experimental conditions. 



Much of an earlier paper already referred to (Herms '07) is 

 taken up with the consideration of field observations. The pres- 

 ent paper is concerned largely with one factor in the behavior of 

 sarcophagid fly-larvae, namely light. 



It has been pointed out earlier that the migrated larvae were 

 found to be active at night, and that migration from the carcass 

 took place openly at night and concealed during the day, i.e., 



IHE JOURNAL OF EXPERIMENTAL ZOOLOGY, VOL. 10, NO. 2 



