THE MOSQUITO 79 



contact, forming starlike patterns. Unlike the 

 eggs of the gnat {Culex)^ the eggs of Anopheles 

 do not adhere together, and the result is they 

 are very readily scattered by the wind. But 

 in sheltered places, like a laboratory aquarium, 

 if undisturbed, the Italian Professor found 

 that they tended to congregate together, as 

 indeed do most minute objects floating on 

 the surface of the water. Our observations 

 did not entirely confirm those of Grassi. In 

 Cambridge, at any rate, we found the eggs in 

 our aquaria always scattered. Very frequently 

 empty egg-shells were met with, but they too 

 were scattered. As a rule, in nature, the ova 

 are deposited in water rich with algae or 

 other vegetable life, and they are more fre- 

 quently in shallow than in deep water, the 

 temperature of shallow water being naturally 

 somewhat higher. 



On the second or third day after ovi- 

 position (and this depends upon the temper- 

 ature), the young larva leaves the egg and 

 begins to swim in the water. The egg hatches 

 by the detachment of a cap-like portion of 

 the anterior end of the egg-shell. There is 

 no visible ring indicating the limits of this 

 operculum, but the cap is usually more or 

 less of the same size. Opinions differ as to 

 how far desiccation interferes with develop- 

 ment of the larva in the egg-shell. They do 



