402 TRANSFORMATIONS OF INSECTS. 



thorax and to the abdominal segments. The bodies of the larvse 

 are not supplied with any respiratory apparatus on their siuos, ^o 

 that the insects can only breathe by elongating and sticking up 

 their tails, which are perforated, and can act as breathing organs. 

 The larvae are found in very briny waters, and even in the water of 

 salt works, and besides in stinking pools. The perfect insect of this 

 rat-tailed creature has a large black body, with russet spots upon 

 the abdomen. 



In the engraving on page 401 the larvae may be seen having 

 two large eyes, a stoutish body, and a long tail. 



If one of them be placed in pure water it will live for a short 

 time, and by just covering the insect at first, and adding water 

 gradually, the tail will be noticed to become erect, and to elongate 

 gradually, so as to keep pace with the flow of water, and always 

 to remain above the surface. After having developed its tail 

 to the utmost, should any more water be added the insect is 

 drowned. 



The Syrphus Fly, or Aphis Eater, is gaily spotted and banded 

 with yellow, so that it resembles a small wasp. They may be seen 

 upon flowers in fine weather, and they lay their eggs upon bushes 

 and plants. The larvae are very small creatures, and are very 

 slender in front, and they walk, or rather crawl over the foliage, 

 principally with the aid of their mandibles. 



They are of a pale green colour, and may often be observed 

 upon rose trees, where they feed upon the plant lice, which they 

 suck and destroy with great rapidity. The larvae of other 

 SyrpJiidcB even attack caterpillars, and manage to eat their way 

 into the bodies of their victims, but they always leave the last 

 segment of the body in the open air, so as to breathe, for the 

 respiratory orifices are situated at the end. 



The true flies, or Mitscidcs, are a great puzzle to those na- 

 turalists who indulge in classification. They have a distinct 

 proboscis, which is thick, membranous, and terminated by two large 

 lobes. It is formed by the united mouth-pieces, and especially by 

 the large lower lip, and the mandibles, which are partly united 

 together, form a sharp blade. These Diptera, which differ so much 

 in the adult stage, resemble each other in the larval condition. 

 The white maggots are so well known that it is not necessary to 



