THE HOUSE FLY 13 



variably is, then hosts of these terrible destroyers of human 

 life cling to the sticky pads on the fly's feet ; on its large, 

 soft proboscis ; on its legs, bristles, and wings. In fact it 

 may be smothered with a vast mass of disease microbes, as 

 well as the putrid filth on which it has fed, and in which it 

 has wallowed. 



We are aware how House Flies swarm over our foodstuffs, 

 drown themselves in our milk, soup, and tea, and sometimes 

 get mixed up with our puddings and pass as currants. 

 Therefore, knowing how the fly becomes covered with 

 disease microbes, any child can understand how those mi- 

 crobes are transferred to our food and drink. Flies have 

 been carefully observed by scientific men in the most pains- 

 taking manner. For instance, flies have been captured at 

 random, and with the aid of a powerful microscope the 

 disease microbes have been examined on them, and even 

 counted. Thus it is known that the majority of flies have 

 from a dozen to millions of disease germs on one or more 

 parts of their bodies. Flies have been watched, and after 

 wading across some choice morsel of food on the dining 

 table, this food material has been carefully examined, and 

 in the track of the fly a line of disease microbes, in many 

 instances, was found. After a few hours it was noted that 

 these disease germs had multiplied and formed great 

 colonies. 



Then milk was taken and carefully sterilised to destroy 

 any microbes which might have been in it. A fly was 

 caught and examined, and if found to have microbes on it, 

 its body was dropped into the milk. The milk was set aside 

 for some hours, and when tested was found to be swarming 

 with the germs of one or more diseases. The microbes, 



