48 SILKWORMS. 



body of a caterpillar, if the work be thoroughly carried out, even 

 without any great aids in the way of high magnifying power, 

 should endeavour to obtain a sight of a remarkable book which 

 was published in France more than a century ago by a most 

 indefatigable worker named Lyonet. It is a large quarto 

 volume, consisting of a treatise of upwards of six hundred 

 pages, on the caterpillar of the Goat Moth, or, as the author calls 

 it, " Le Chenille qui ronge le bois de Saule," i.e., the caterpillar 

 that eats the wood of the willow. It is illustrated by a large 

 number of plates, in which are depicted with marvellous care and 

 accuracy numerous dissections of the animal, showing the disposi- 

 tion of its digestive, nervous, respiratory, muscular, and other 

 organs with most extraordinary minuteness. If that painstaking 

 observer had lived a century later, and undertaken his work with 

 all the appliances of the modern microscope, he could easily have 

 doubled the size of his book. 



We are now provided with the necessary information for con- 

 sidering the position of the silkworm in the animal kingdom. 

 The facts that it possesses no skeleton of bones or other hard 

 parts inside, and that its muscles are attached to the inner surface 

 of an outer hard covering (the leathery skin of the caterpillar, 

 or the horny covering of the chrysalis and moth), instead of to 

 internal hard parts, show that it belongs to the great Invertebrate 

 section of the animal kingdom, or that division which contains 

 all animals without a backbone or its representative. We have 

 shown that its body is composed of a series of segments, that it 

 has jointed legs, and that its nervous system consists of a double 

 chain of ganglia ; these facts indicate that it belongs to the most 

 extensive of all the invertebrate sub-kingdoms, viz., the Ar- 

 thropoda, where also are located all such animals as crabs and 

 lobsters, shrimps, spiders, scorpions, mites, centipedes, beetles, 

 bees, grasshoppers, etc. Again, it breathes by tracheae ; its body, 

 when mature, consists of three parts head, thorax, and abdomen ; 

 it has at the same time six legs and four wings ; these are 

 peculiarities of structure which cut it off from several of the above- 

 named creatures, and indicate that its proper place is in the 

 class Insecta, or Insects, the largest and most highly developed 

 group of all the Arthropoda. 



But this class contains an enormous assemblage of creatures 

 of the most varied types, and we must again appeal to the 

 structure of our insect to determine in what order of the class 

 it is to be placed. The two facts that its four wings are covered 

 above and below with feathery scales, and that it passes through 

 the experiences of caterpillar, chrysalis, and moth life, are suffi- 



