THE YOUNG NATURALIST. 



173 



Soma species can pierce what they desire to 

 suck, others can only use their trunks for 

 liquids, or substances they can liquify. The 

 antennae are often very short. The eyes are ; 

 generally very large, and often take up nearly 

 the whole of the head. The larvae are of j 

 immense value as scavengers, and devour, as 

 ve have already said, enormous quantities of ! 

 food, in an incredibly short space of time. 

 They breed quickly, and generation succeeds 

 generation with almost incredible rapidity. 

 The larva of the Blue-bottle (Calliphora 

 vomitoria) is said to arrive at maturity in four 

 or five days. The eggs hatch within 24 hours 

 of being laid, and housewives know how 

 quickly they will spoil a piece of meat. The 

 larva of the common Housefly (Musca domes- 

 tica ) is more of a vegetable feeder, the eggs 

 being deposited on decaying vegetables, and 

 particularly in horse or cow dung. It is said 

 that in Venice, where there are no horses, 

 there are no house flies. If this be so, we 

 would, as is suggested by Kirby and Spence, 

 greatly reduce the number of these pests, by 

 keeping stables, &c, in a cleaner state. 

 Bruce, the Abyssinian traveller, was scarcely 

 believed when he spoke of the destruction of 

 cattle by a small fly, but Livingstone and 

 others have fully investigated the matter. 

 The Tsetse (Glossina morsitans) is very little 

 larger than the House fly, and, as described 

 by Livingstone, is fatal to all domestic 

 animals except the goat. It inserts its pro- 

 boscis through the outer skin, and witbout 

 apparently disturbing the victim, sucks its 

 fill and then departs. No evil effect appears 

 to be prcduced for a few days, then the eyes 

 and nose begin to run, swellings appear, and 

 though the animal continues to take its food 

 as usual, it becomes more and more emasciated, 

 and eventually dies of exhaustion, perhaps 

 some months after it had been bitten. In 

 man no ill effect is produced, and, singular to 

 say, calves are uninjured if bitten while suck- 

 ling. There are many other flies that are 

 fond of blood, even human blood. What 

 Entomologist has not been bitten by gnats. 



The bite of these little insects produce very 

 different effects on different people. On some 

 they cause painful lumps to rise, that itch 

 intolerably. No doubt the Gnat, as well as 

 the Tsetse inject some obnoxious or poisonous 

 liquid into the wound, and it is astonishing 

 how great an effect a very small quantity 

 produces. Besides the injuries done by the 

 injection of poison into the wound when suck- 

 ing, many diptcra inflict greater injury on our 

 domestic animals by the insertion of their 

 eggs in various parts of their bodies. At 

 page 46 (No. 6) you will find an account of 

 the manner in which the Gadfly manages to 

 convey its young to the inside of the stomach 

 of a horse, but it is probable that these do not 

 inflict serious injury in the animal, as they 

 pass out with the excrement when ready for 

 their next change. The Bot fly (JEstrvs bovis ) 

 inserts its eggs under the skin of cattle, the 

 larva? feeding there, and raising a lump upon 

 it. The Breeze liy attacks sheep, depositing 

 its eggs about the nostrils whence the larvae 

 penetrates further into the head. Some 

 species are said to deposit their eggs on man, 

 but we do not know that there is any fly, the 

 proper food of whose larvae is the flesh of 

 human beings. While some flies thus devour 

 in their early stage living flesh, the perfect 

 insect will perhaps be content with the juices 

 of plants, or honey from flowers. In some 

 species, the Tabanida for instance, the females 

 are blood suckers, while the males frequent 

 flowers. We must not omit to mention the 

 Crane flies, (Tipulida), or "Daddy long legs" 

 as children call them. The larvae of these 

 are said to feed on soil, if so, it will probably 

 be soil much impregnated with decaying 

 vegetable matter. The eggs are often laid in 

 the decaying trunks of trees. The perfect 

 insects are too well-known to need descrip- 

 tion. One might well wonder of what use to 

 such an insect, are its long feeble legs, but 

 they generally frequent grassy land, and the 

 wide spread of their limbs will prevent them 

 sinking down among the blades of grass. The 

 powers of flight of some of the dipteva are 



