I08 TRANSFORMATIONS OF INSECTS. 



is celebrated for containing the Bombyx mori — the mulberry cater- 

 pillar or silkworm. This genus Bombyx has been sub-divided, 

 so that now this well-known pet amongst children, and great care 

 amongst silk growers, is called Sericaria. 



This insect is so well known that no description of its rapidly- 

 growing caterpillar, the lazy chrysalis, and the quiet moth that 

 never eats or sucks, is necessary. What a plain, ugly moth it 

 is, and what a common looking grub comes from the ^%Z. 

 There is nothing charming, no bright tints, and no delicate 

 ornamentation ; moreover, it is rather clumsy looking. None 

 of the graces of form or the magnificence of the colouring 

 of the Lepidoptera that enliven the shades of the grandest 

 flowers are here. The caterpillars of some species of the 

 genus are even handsome, and have pretty green globular 

 ornaments on their segments, and others like coral and pearl ; 

 but the humble silkworm has none of these. Its beauties are 

 intrinsic, and it yields the most beautiful web that Nature can 

 produce, to render, if possible, the loveliest of all created things 

 more attractive than ever. The comparison of the silkworm 

 caterpillar with those of other moths soon enables us to dis- 

 tinguish between the SpJiingidcg and the Bombycidce, and to 

 notice how much they are alike in structure generally speaking. 

 The silkworm caterpillar resembles those of some sphinges in 

 its shape, and in its having the tubercle on the last segment 

 but one of the body, but it differs from all by having its silk- 

 bearing glands enormously developed. When a full-grown silk- 

 worm caterpillar is opened, the intestinal canal will be seen to 

 fill the greater part of the body, and on either side of the stomach 

 and gullet there will be observed a large twisted tubular gland. 

 This is the silk gland, or rather, of that viscous matter, which 

 as it is drawn out, hardens into silk. These glands pass under- 

 neath the gullet, and each is continued in the form of a narrow 

 tube to the mouth ; they unite before reaching the head, and 

 form one canal, into which open the ducts of two little glands, 

 whose function is to unite the silken threads of the silk tubes, 

 to varnish and brighten them, and to give them that perfection 

 of texture we all admire and value. The canal opens in the 

 lower lip or labrum, and passes through a small opening in a 



