242 FLASHLIGHTS ON. NATURE 



draught of air (just like a whale or a porpoise) and 

 is darting to the depths again. The tiny valves 

 or doors are now closed, so that no water can get 

 in ; the larva will go .on upon the air thus stored 

 till all of it is exhausted ; he will then rise once 

 more to the surface, let out the breath loaded 

 with carbonic acid, and draw in a fresh stock 

 again for future use. 



NO . 6. THE PUPA OR CHRYSALIS, BREATHING THROUGH 

 TWO HORN-LIKE TUBES 



The young mosquito remains in the larval form 

 for about a fortnight or three weeks, during the 

 course of which time he moults thrice. As soon 

 as he is full-grown, he becomes a pupa or chry- 

 salis lies by, so to speak, while he is changing 

 into the winged condition. No. 6 is a faithful 

 portrait of the mosquito in this age of transition. 

 (I borrow the last phrase from the journalists.) 



