OF NATURAL HISTORY. 293: 



for feveral months before their laft metamorphofis takes place. In 

 a word, it feems to be a lifelefs mafs. But, upon a more attentive 

 obfervation, it pofleffes the power of bending upwards and down- 

 wards the pofterior part of its body. The fkin, or exterior cover- 

 ing, of thofe which do not fpin cods, feems to be of a cartilaginous 

 nature. It is commonly fmooth and fhining. In fome fpecies, 

 however, the fkin of the chryfalis is more or lefs covered with hair, 

 and other rugofities. Though chryfalids differ both in figure and 

 colour, their appearances are by no means Co various as thofe of the 

 caterpillars from which they are produced. The colour of fome 

 chryfalids is that of pure gold, from which circumftance the whole 

 have received their denomination. For the fame reafon they are 

 ealled attreliae in Latin. Some are brown, others green; and, indeed^ 

 they are to be found of almoft every colour and fliade. 



The life of winged infefts confifts of three principal periods,, 

 which prefent very diiferent fcenes to the ftudent of Nature. In 

 the firft period, the infedl appears under the form of a "worm or ca- 

 terpillar. Its body is long, cylindrical, and confifts of a fucceffion 

 of rings, which are generally membranous, and encafed within each 

 other. By the aid of its rings, or of crotchets, or of feveral pairs of 

 legs, it crawls about in queft of food ; and its movements are, in 

 fome fpecies, remarkably quick. Its head is armed with teeth, or 

 pincers, by which it eats the leaves of plants or other kinds of food. 

 In this ftate, it is abfolutely deprived of fex, and, confequently, of 

 the power of multiplication. Its blood moves from the tail toward 

 the head. It refpires either by ftigmata or fmall apertures placed on 

 each fide of its body, or by one or feveral tlabes fituated on its po- 

 fterior part, which have the refemblance of fo many"tails. In the fe- 

 cond period, the infedl appears under the form of a nymph, or that 

 of a chryfalis. When an infeft, after throwing off the fkin of the 

 eaterpillar, exhibits all its external parts, only covered with foft and 



tianfparent- 



