GROWTH OF SILK-WORMS. 167 



stance al)out 60,000 times its primitive weight. In 

 warmer climates, silk-worms consume a rather less 

 quantity of leaves, because these are perhaps more 

 nutritive; but, in that case, the silk produced is not 

 so delicate and fine. The li)llo\\ing statements are 

 the result ol' experiments made by Count Dandolo: — 

 Progressive increase of silk-worms in weisiht. 



CHAINS 



A hundred worms just hatched weigli about 1 



After the lirst moulting 15 



After the second moulting 94 



After the third moulting 400 



After the fourth moulting 1<)28 



On attaining their greatest size and weight 9500 



They have, therefore, in thirty days increased 9500 

 times their primitive weight. 



Progressiie increase of silk-worms in length. 



LINES. 



A silk-worm just Iiatched measures about 1 



After the fust moulting 4 



After tiie second moulting 6 



After the third moulting 12 



After the fourth moulting 20 



After tlie tiflh moulting it may roach 40 



The length of the silk-worm, therefore, increases 

 about forty times in twenty-eight days.* 



By recalling to memory the comparisons of the 

 etrgs of insects with the seeds of plants, and of cater- 

 pillars with buds, which ought to be taken (if we 

 mav trust Swarnmerdam) literally rather than poeti- 

 caliy, we shall arrive at more distinct notions of 

 tlie manner in which the growth and changes of 

 larvtc are accomplished. The buds of plants are 

 com-josed of successive leaves closely embosomed 

 within each other's tcildings, the outer one being 

 generally hard and corneous, from the e.xposure of 

 its vessels to the colds of winter, while the inner 



* Count Dandolo on .-illv-worms, p. 326, F"ng. Trans. 



