248 ANIMAL LIFE 



nourishment, forcing into rapidly recurring broods the 

 development of their young. 



Our common flies are highly organised. Though 

 the house-fly is the first animal we meet, it is the last 

 we know. Concerning it, as of most familiar animals, 

 Aristotle's apophthegm holds good, that what is first 

 in nature is last in genesis. The fly, like all beings, is 

 an old hand, yet historically it^ is a new-comer, and 

 proclaims the fact in its structure, habits, and life- 

 history. We may therefore lead up to it by some less 

 specialised forms — namely, the mosquitoes. 



Of this large family the gnats, mosquitoes proper, 

 and the harlequin flies may be taken as examples. 

 The first may be roughly distinguished by its habit 

 of resting on its fore and middle legs, holding the last 

 pair in a raised position ; the second, by its yellow and 

 black colouring ; and the last by its habit of raising 

 the fore-legs when at rest. 



The Gnat. — The two sexes of the common gnat arc 

 easily distinguished. The male has bushy antenna;, 

 the female has slender antenna with inconspicuous 

 hairs inserted at each joint. The males associate in 

 large companies that dance over the country-side, 

 whilst the female is more solitary and rests often in 

 outhouses and near or in dwellings. Lastly, the blood- 

 sucking habit is peculiar to the female. 



In early summer the female lays her eggs in little 

 boat-shaped floats, on the surface of water standing 

 in butts or on marshy ground. The float is rather 

 less than a quarter of an inch long, and contains 



