84 



MALCOLM EVAN MACGREGOR. 



No doubt the duration of the resistant period may be altered by the length of 

 time that the eggs are first in contact with water. 



Fig. 2. Collapsed eggs of Stegomyia fasciata. X 20. 



Figs. 2 and 3 are photomicrographs of eggs from the same batch. Those in Fig. 2 

 were removed from the water about 15 hours after they had been laid, and were allowed 

 to dry on filter-paper at the laboratory temperature (64° F.). They had completely 

 collapsed 15 minutes after being placed on the paper. 



Fig. 3. Resistant eggs of Stegomyia fasciata, X U. 



