Ecological and Experttnefital Study of Sarcophagidce 75 



bilities are that such individuals would suffer starvation. If this 

 were often repeated the tendency would be to impair the vigor of 

 the species, especially by interfering with the normal egg-laying 

 habit. This latter would certainly be the case if the usual number 

 of adults were to emerge with an undersupply of food present upon 

 which the eggs could be deposited. The large number of larvae 

 for the short supply of food would result in producing smaller indi- 

 viduals, which has been proven by experiments. That the sarco- 

 phagids given in the list are normal, as compared with individuals 

 of the same species breeding elsewhere, is evident to the most super- 

 ficial observer, and they are certainly not less numerous. 



Considering the above facts and also bearing in mind that the 

 food supply is influenced by the comparative regularity of the 

 surfs, there seems then to have been somewhere in the past an 

 adaptation to the surf-producing storms. When the adult fly 

 emerges from the pupa case it is likely to find available food on 

 the beach, or has but a very short time to wait for it. Then since 

 egg deposition and food supply are so intimately connected, eggs 

 are deposited and the cycle begins anew. 



As soon as the liquids have been sucked from the accessible 

 parts of the fish, egg-laying ceases and the remainder of the work 

 is left to the larvae. The presence of juices would then seem to 

 be a gauge for regulating the number of eggs and young larvae 

 deposited on one fish by the females. This will recall the state- 

 ment made above that eggs are seldom if ever deposited on fish 

 that have become dry, which fact should also be borne in mind in 

 connection with, the adaptation to the surfs. If fish were to lie 

 around for any length of time before the flies emerge, the juices 

 would be dried up by the sun, and the fish would become unfit for 

 food. However, it is very probable that the adults would after all 

 deposit eggs on the dry fish. Lack of food for the adults would 

 necessarily be a serious menace to the species. Under conditions 

 as they now exist a drying out of a fish by the sun would not likely 

 occur, since the flies would not permit a single fish to dry out thus. 

 The assertions relating to this are based on laboratory experi- 

 ments, I. ^., drying out a fish in the laboratory and then placing it 

 outside in reach of flies. 



