98 



THE INSECT WORLD. 



water, on the mud, and does not avoid the hand put out to seize it. 

 Its body is terminated by a tail, composed of two grooved threads, 

 which, when appHed together, form a tube, capable of being moved 

 from side to side. Through this canal it breathes the outer air ; it 

 puts the end of it out of the water, and the air enters it by inspiration. 

 Some very small hairs, with which the interiors of the grooves are 

 lined, interlace each other, and prevent the water from penetrating 

 into the canal. It is probable that this same canal serves also for 

 depositing the eggs. These last resemble small seeds, covered with 

 points, and are buried in the stalks of aquatic plants. 



Next to the Nepa comes the Ra7iatra^ with a cylindrical, elon- 

 gated, linear body, with very long and very thin hind legs, and of 



which one species, which Geoifroy 

 calls the "aquatic scorpion with an 

 elongated body," is common every- 

 where in stagnant waters in spring. 

 It is brownish, carnivorous, and very 

 voracious. 



We must now mention the genus 

 Co7-ixa, of which one species, the 

 Corixa striata^ is very common. This 

 insect walks badly and slowly on land, 

 but swims and cuts tlirough the water 

 with a prodigious rapidity. 



However, it is not to delay over 

 this last species that we have here 

 mentioned the name of this genus. Some insects which belong to 

 it, and which are found in Mexico, deserve to be alluded to, on 

 account of certain peculiarities which their eggs present. A natu- 

 ralist, M. Virlet d'Aoust, has published the following details on this 

 subject : — 



" Thousands of small amphibious flies," he says, " flit about in 

 the air on the surface of lakes, and diving down into the water many 

 feet, and even many fathoms, go to the bottom to lay their eggs, and . 

 only emerge from the water probably to die close by. We were 

 fortunate enough to be present at a great fishing or harvest of the 

 eggs, which, under the Mexican name of hauile {haont/e), serve for 

 food to the Indians, who seem to be no less fond of them than the 

 Chinese are of their swallows' nests, which they resemble somewhat I 

 in taste ; only the hautle is far from commanding such high prices 

 as the Chinese pay for their birds' nests, which for that reason are 

 reserved entirely for the tables of the rich ; while, for a few small 1 



Fig. 76. — Corixa striata. 



