last few years, particularly in America and this country, and, 

 thanks to the observations of Lowne (1890), Howard (1912), 

 Newstead (1907 and 1909), Griffith (1908), Hewitt (1910), 

 and Graham Smith (1910), we are now well acquainted with 

 this insect, which has perhaps most obtruded itself upon the 

 attention of man, but intimate knowledge of which was, 

 until recently, curiously lacking. 



Life- History. 



The female fly produces about 120 eggs at each laying, and 

 may produce four broods. Under ordinary conditions the 



FIG. 1. 



I) 



A, The egg. B, The larva emerging, c, The half-grown larva. 

 D, The pupa. 



eggs are mostly laid on horse, pig, or cow manure, but the 

 excreta of almost any animal, or other fermenting refuse, 

 suffices. (Fig. 1.) The eggs are sausage- shaped with one 

 end sharp, glistening white in colour, and about 1*5 mm. 

 in length and 0'3 mm. in their greatest diameter. The eggs 

 hatch in from three days to eight hours, according aj the 

 temperature ranges from 50 to 80 F. The larva is a little 

 active grub 2 mm. long, with a sharp anterior and a blunt 

 posterior end. The larval stage lasts from five days to three 



