DAHLGREN, THE MALARIA MOSQUITO 



11 



star-shaped groups or adhering side by side to make miniature 



pontoon-bridges (Fig. 6). The eggs of certain species are never 



laid on water, but 



on mud, perhaps at 



the edges of pools, 



and are said not to 



develop at all, unless 



they be left dry for at 

 least twenty- 

 four h o u r s . 

 is of 



FLOAT 



SIDE VIEW 



AIR CHAMBERS WHICH ACT AS FLOATS 



| ' v,- 



-7— ^:::y 



Resist- 

 ance 



The 



some mosquitoes will 

 survive drying for two 

 or three months, while 

 those of others with a 

 thinner chitinous shell , 

 easily perish if the 

 mud or water of the 

 pool in which they 

 have been laid dries 

 up. Ordinarily, mos- 

 quito eggs are not resistant to cold and will not survive freezing, though 

 those of some species are actually known to hibernate. 



SURFACE VIEW 



FROM NUTTAL AND SHIPLEY 



FIG. 4. THE EGG OF THE MALARIA MOSQUITO. 



Magnification about 60 diameters. 



FIG. 5. " EGG-RAFT " OR EGG-BOAT OF THE COMMON HOUSE MOSQUITO 



(Cviex pupiens Linn.). 

 .Magnification 12 diameters. 



^Yhen the egos are readv to hatch, in about two to four days after 

 they are laid, a small cap-like portion of the envelope Hatching 

 bursts off at the rounded end of the egg and the larva escapes. 



J 



