HOW TO COLLECT MOSQUITOES 227 



specimens can be taken out and preserved, to illustrate 

 variations of different stages of g-rowtli. Accurate notes 

 can be kept as to temperature, periods of transformation, 

 and so on. A series of dates, provided several jars are 

 under observation, can be written from time to time upon 

 a slip of paper, which may be pinned to the edge of the 

 cloth-covering- of each jar. 



Where the eg\gs of Anopheles, for example, have not 

 been found, females collected at large may be liberated 

 in such a prepared breeding-jar. They will rest on the 

 under side of the cloth-covering during the day and at 

 night will lay their eggs on the surface of the water. It 

 is desirable to have a stick in the water, or a leaf, or a bit 

 of cork, floating on the surface. I have had no difficulty 

 in obtaining the eggs of Anopheles in large numbers in 

 this way and the eggs of Culex as well, but although as 

 many as fifty females of Psorophora have been liberated 

 in breeding- jars i)repared in this way, I have not been 

 able to get the eggs of this genus, which, as a matter of 

 fact, are yet unknown. It is possible that Psorophora does 

 not deposit its eggs upon the surface of water. This, 

 however, is unlikely and it is rather to be supposed that 

 the females used in my experiments were not old enough 

 for oviposition and died from the confinement of the jar 

 before the egg-laying period arrived. 



When one wishes to study closely the movements and 

 intimate habits of the early stages of mosquitoes a great 

 deal may be observed through the glass sides of the jar, 

 by using a coarse lens and studying those near the edge. 

 But when a closer study is desired, individual larvae or 



