TRANSFORMATION OF ANIMALS. 163 



legs in a tuft of silk. After transformation, the chrysalids re- 

 main fixed in the same manner as before their metamorphosis. 

 The belt is loose, and allows the chrysalis to perform its slow 

 and feeble movements. 



The whole moth kind, as well as the silkworm, immediately 

 before their transformation into the chrysalis state, cover their 

 bodies with a cod or clew of silk, though the nature of the 

 silk, and their mode of spinning, are very different. The cods 

 of the silkworm are composed of pure silk. Their figure is 

 generally oval, which necessarily results from that of the ani- 

 mal's body upon which they are moulded. When spinning, 

 they twist their bodies into the form of an S. The cod is 

 produced by numberless circumvolutions and zigzags of the 

 same thread. The silk is spun by an instrument situated 

 near the mouth of the insect. The silky matter, before it is 

 manufactured by the spinning instrument, appears under the 

 form of a gum almost liquid, which is contained in two large 

 reservoirs contorted like the intestines of larger animals, and 

 which terminate at the extremity by two parallel and slender 

 conduits^ Each conduit furnishes matter for one thread. 

 The spinning instrument, as is evident when viewed by the 

 microscope, unites the two threads into one. Thus a thread 

 of silk, which has the appearance of being single, is in reality 

 double, and spun with great dexterity. Some writers, who 

 delight in the marvellous, ascribe foresight to the silkworm 

 in spinning its cod. The silkworm, it must be acknowledged, 

 acts as if it foresaw the approaching event. But the truth is, 

 that, when the animal has acquired its full growth, its reser- 

 voirs of silk are completely filled. It then seems to be strongly 

 stimulated to evacuate this glutinous matter. Its different 

 movements and attitudes, while discharging the silk, produce 

 those oval bundles which clothe and ornament vast numbers 

 of the human species. 



Another species of caterpillar constructs its cod in the form 

 of a boat with the keel uppermost ; but it consists not en- 

 tirely of pure silk. The animal, with its teeth, detaches small 

 triangular pieces of bark from a bush or a tree. These 

 pieces of bark it pastes upon its body, by means of a glutinous 

 or silky substance, and they constitute a principal part of 

 its cod. 



Another species works also in wood, though not with as 

 much art as the former. Its cod is composed entirely of small 

 irregular fragments of dried wood. These fragments the ani- 

 rnal has the address to unite together, and to form of them a 



