first of all into the crop. When this is full some goes into 

 the stomach. In the case of solid material, such as sugar, 

 dried blood, or sputum, the insect must first dissolve the 

 material. This is done by pouring saliva upon it, or more 

 generally by regurgitating some of the contents of the crop 

 (Graham Smith, 1910). 



Graham Smith (1910) by feeding experiments with coloured 

 syrup found that the meal was first taken into the crop, and 

 subsequently transferred to the stomach at leisure. The fly 



FIG. 4. 



-CF. 



Front view of a fly's head, showing proboscis and chitinous 

 channels (CH) ; E, K, Eye. 



could, however, fill first its crop and then its stomach. In a 

 quarter of an hour the meal had passed on to the upper third 

 of the intestine, and in a warm incubator at 37 C. reached 

 the rectum within an hour. The fly seems to keep some of 

 the fluid in its crop for days. 



A well-fed fly deposits faeces abundantly. Graham Smith 

 (1910) noticed flies defascatingten times in the first hour after 

 feeding. A curious habit of flies to which, as far as I know, 

 attention was first drawn by Graham Smith, is the regurgitation 

 of the contents of their crops. This has already been referred 

 to as a means by which they are enabled to feed upon dry 



