272 NATURAL HISTORY. 



it little apartments occu- 

 pied by the larvae, as you 

 see in the figure. In Fig. 

 211 you have one of the 



Fig. 211 Magnified Bristle of the Gall, bristles magnified. 



465. The insects of the Ichneumon family have long, 

 slender bodies, long ovipositors, and long antennae, which 

 are in a continual trembling motion. The ovipositor of 

 some species is exceedingly long, as in Fig. 212 (on the 

 opposite page). The two bristles accompanying the ovi- 

 positor can be brought together by the animal so as to 

 make a complete sheath for it. These insects deposit 

 their eggs in the bodies of the larvae of other insects, and 

 the larvae hatched from them live on these bodies just as 

 the gall insects live on the galls in which they are hatch- 

 ed. Those which have long ovipositors pierce with them 

 the bark of trees or decayed wood, in order to find larvae 

 in which they can deposit their eggs. Those which have 

 shorter ovipositors deposit their eggs in the bodies of 

 caterpillars which they find crawling about. We some- 

 times see a caterpillar with a considerable number of 

 little barrel-shaped silken bodies standing out upon its 

 skin. These are the cocoons of the Ichneumon larvae, 

 which, after living for some time in the fat of the cater- 

 pillar, just under its skin, have come out and have spun 

 their cocoons, that they might go into the pupa state. 

 The Ichneumon family is very numerous. Carpenter 

 states that there are probably over three thousand spe- 

 cies in Europe alone. 



466. The Chrysididae, or Ruby-tailed Flies, are a small 

 group, adorned with such brilliant metallic tints that they 

 have been said to be the Humming-birds of the insect 

 world. The females deposit their eggs in the nest of 

 wild Bees and other Hymenoptera, and thus the larvae 

 eat the food designed by these latter for their own off- 

 spring. Here is a striking analogy to the habit of the 

 English Cuckoo, alluded to in 268. 



