228 



white and striated, and probably represen1,s the 

 upper surface of other Anopheltne ova. 



2. There are no floats or any markings 

 representing them. 



3. There is a pale area at the thicker end of 

 the egg with a scalloped edge. 



4. The ovum is otherwise without markings. , 

 It is otvious that the characters of the ovum 



are of considerable importance in the classification 

 of Anophelines, and every care should be taken to 

 describe these in as great detail as possible. 



In making drawings of the ova of Anophelines, 

 it is convenient to use an eyepiece micrometer. 



To Mount Ova 



No thoroughly satisfactory method is known 

 to us, but although imperfect, any of the following 

 methods will give specimens in which some, at 

 least, of the ova preserve most of their charac- 

 teristics. 



1. Place the eggs on a slide which has been 

 made slightly sticky with balsam, and then mount 

 them in a drop of balsam and place a cover-glass 

 over them. 



2. Mount in two per cent, formalin solution 

 and ring the coverglass with balsam or shellac. 



3. Mount in glycerine and ring the specimen. 



4. Mount in a drop of cedar- wood oil. 



