METAMORPHOSES OF INSECTS. 43 



species, being dotted, or sprinkled, with yellow and 

 black, instead of having the colors well defined. If 

 the young naturalist will take a sprig of the parsley, with 

 one of these on it, and put the whole into a glass jar, or 

 other place of confinement, taking care to water the 

 plant, he will soon find it to be identical with the large 

 ones. 



This larva is remarkable for having on the back of 

 the neck, an instrument composed of two fleshy horns, 

 branching from a common stem somewhat like the letter 

 Y. This organ appears to be similar in some respects 

 to the horns of snails, and is capable of similar move- 

 ments, being completely retractile. When the animal 

 is irritated these horns are projected, and it appears 

 from the observation of Reaumur, that this organ se- 

 cretes an acid liquor, which emits the unpleasant smell, 

 and which every one who has touched one of these w r orms 

 cannot but have perceived. Reaumur supposes that 

 this acid is a means of defence against the attacks of the 

 ichneumon, a small fly which deposits its eggs in the 

 flesh of the larvae of various insects. 



This larva, when spinning the silken cord by which it 



27. Fig. 28. * S tO ^. e su PP orte d m ^e 



chrysalis state invaria- 

 bly fixes it around the neck 

 at the junction of the fifth 

 and sixth segments, where 

 there is a cavity in which 

 it is kept from sliding back- 

 wards or forwards. This 

 cord appears to pass un- 

 der the skin of the chrysa- 

 lis, but on examination 

 with a magnifier, it will 

 be seen, only almost con- 

 cealed in a deep channel. 

 The larva and its chrysa- 

 lis, both of the natural 

 size, are represented by Fig. 27 and 28 ; the latter being 

 suspended by the cord in the manner described. 



