52 fVilliam B. Herms 



plump migrating larvae. Since these birds are quite numerous 

 along the beach one can readily see that this would be a potent 

 factor in extermination, and some means of protection is very 

 advantageous. During the night, or w^hen the sand is cooled, 

 migration from beneath the remains takes place, and it is then that 

 the larvae travel a greater distance — fifteen, twenty feet and over, 

 and then again burrow. Larvae that were kept indoors in boxes 

 were observed to repeat this performance several nights in suc- 

 cession, each time burrowing for the day. The sand in the 

 laboratory was not heated by the sun, yet the larvae followed 

 their normal habit and were characteristically active by night. 



Ants are a minor source of destruction to the larvae that migrate 

 from fish which have been dragged a distance away from the 

 water. Live larvae, wriggling frantically, are carried away by 

 these little marauders. 



At noon of August lo, 1905, several dozen larvae were found 

 lying dead upon the sand, within a radius of about five feet from 

 a fish. The sand was extremely hot, about 140° just below the 

 surface, and the larvae had been literally baked. What induced 

 this attempt to migrate from the fish at this time is a question. 



Piipati 



on 



The interval between migration and pupation varies. With 

 individuals reared indoors this interval varies with the degree of 

 moisture — extreme moisture retarding pupation, as also does 

 extreme dryness. A certain amount of moisture is necessary for 

 pupation; therefore, a small amount of water was added to the 

 sand in which the indoor individuals were kept. Temperature 

 probably also affects this stage. All observations were made 

 during the summer months, consequently what happens in spring 

 and autumn later than the middle of September is still open for 

 investigation. The deep loose sand of the beach affords a uni- 

 form condition for the burrowing larvae and for pupation. This 

 condition, together with the food supply, also comparatively uni- 

 form, would naturally cause less variation in the life histories of 

 species here than in parts remote from the beach. 



