20O 



INSECT TRANSFORMATION 



The pupa (Fig. 103 D) of Anopheles resembles, in its main 

 features, that of Culex. The respiratory " trumpets " (/) on 

 the prothorax are jointed, and strongly expanded at their 

 free ends ; it has been observed that when the pupa leaves the 

 surface it often carries down with it a small air-bubble attached 



FIG. 104. POSITION OF LARVAL Cltlex (a, SIDE VIEW, 6, END VIEW) AND 



Anopheles (c, SIDE VIEW ; d, END VIEW), WHEN BREATHING AT SURFACE 



OF WATER. X IO. 



After Howard, U.S. Dept. Agric. Ent. Bull. 25. 



to the opening of each. This pupa swims actively by means of 

 rapid strokes of its flexible abdomen which carries a pair of 

 fin-like flaps at the hinder end. 



It may be remembered that a change in the position of the 

 functional spiracles from the tail of the larva to the prothorax 



