MUSClMJ. 
645 
To avoid having the house and kitchen infested with flies is a matter 
of importance to health, since the insects carry on their feet and other 
parts of the body traces of the filthy matter on which they are accustomed 
to sit and suck, and are liable to infect our food and milk with the germs of 
stomach-diseases derived from this filth. Kitchens should be kept 
very clean, and no refuse of any kind allowed to lie about in the kitchen 
or near it. All food when not in use should be kept in close-shutting 
wire meat-safes, or at least so covered that no flies can get at it. 
Particular care should be taken in the safe disposal of night-soil. 
The blue-bottles of India belong chiefly to the genera Lucilia , Pyc- 
nosoma, Thelychceta, and Pyrellia, while the common English Calliphora 
erythrocephala, Mg., occurs in the hills, but not in the plains. They are 
much less common in houses than are the house-flies of the genus Musca, 
and a considerable number of their larvae live only in decaying flesh or 
other animal matter. It is perhaps owing to the quickly-perishable 
nature of this food that so many of the blue-bottles lay such a large 
number of eggs as compared with the house-flies. The fly shown on 
PI. LXIX, fig. 5, as Idia, illustrates a distinct type of Muscid with 
a prominent face and proboscis. Species of Idia or Rhynchomyia are 
not uncommon on flowers and may be recognised easily by their 
peculiar dull metallic look, quite unlike that of most Muscidce. The 
larvae are said to be parasitic on other insects. 
There remain the important group of blood-sucking Muscidce. 
There is no easily recognisable character which will separate them from 
many other flies of similar general appearances ; the best character is 
that they suck blood. The importance of obtaining accurate knowledge 
of the distribution and habits of these blood-sucking Muscidce is, from 
the point of view of the stock-owner and breeder, very considerable, 
since it is extremely probable that these flies, together with some of the 
Tabanidce, are able to carry from one animal to another, the parasite 
which causes the very serious disease known as “ Surra ” (Trypanoso¬ 
miasis). This parasite is extremely minute, quite invisible unless 
looked at through a microscope, and when seen alive in the blood of the 
diseased animal it has rather the appearance of a wriggling eel with a 
somewhat flattened body. An almost exactly similar parasite is the 
cause of the generally fatal human disease in Africa called “ Sleeping- 
sickness,” and this latter parasite is carried from man to man in the 
