620 INSECTS AT HOjME. 



and protected in every mode that lies in the power of civilised 

 man. 



To return for a moment to our larva. It is impossible that 

 any creature could obtain air while buried in the thick mud 

 which has just been described. There are many creatures, 

 especially Crustacea, which do live bm-ied in mud, but then 

 they always form a slight tunnel, so that they are really 

 immersed, not in mud, but in water. The Eat-tailed Maggot, 

 however, is really buried in the mud, and needs some apparatus 

 for communicating with the air. This apparatus is supplied by 

 the telescopic tail of the larva, which can be projected out oi 

 the mud, and by means of the double air-tubes which it 

 contains conveys the necessary amount of oxygen to the system. 



The ' tail ' can be retracted with great rapidity. I had a 

 great number of the larvse in a bottle, on the bottom of wliich 

 was placed a layer of mud in which the creatures could bury 

 themselves, and the rest of the bottle nearly filled with water. 

 When all was quiet, all the tails remained quite upright, and 

 looked like a number of young aquatic plants. But if the 

 slightest jar were given to the bottle, all the tails were 

 retracted, and the water was left clear and empty as if by a 

 conjuring trick. 



"When the larva is full-fed on the disgusting substances 

 which form its dainties, it extricates itself from the mud by 

 means of seven pairs of tiny hooked feet, crawls ashore, buries 

 itself in the earth, and there awaits its change. The larval 

 skin then shortens and hardens, and the pupa separates itself 

 from its former skin, which then acts the part of a cocoon. In 

 jjrocess of time the transformation is complete, and the dull 

 motionless grub that had passed its whole life sunk in the dark 

 and obscene mud is transformed into a creature of light, gifted 

 with enormous eyes and glittering powerful wings, and darting 

 through the air with a rapidity so great that the eye cannot 

 follow its track. The specific name of tenax is given to the 

 insect on account of the tenacity with which it holds to any 

 object that it may grasp with its feet. 



On Woodcut LXXII. Fig. 3 is represented an insect called 

 Merodon davipes. 



In this genus the body is blunt and hairy, the third joint of 



