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dififerent parts ; but supposing we luke our own mouth for 

 an example — the upper lip represents the labrium, the lower 

 lip the labium; the upper jiw being divided into two, form 

 the mandibles which act laterally and like a pair of 

 scissors, the lower jaw being equally divided form the 

 maxillae, or feelers. Inside the lower lip there is a small 

 nipple shape protuberance ; this is the fusculus, or 

 spinaret, and here exudes that plastic matter which, harden- 

 ing as soon as it escapes, becomes silk, varying in quality 

 as regards the insect producing it, and the manner in 

 which it spins its cocoon, same as in Barabyx Morii or a 

 common silk-worm. This larva spins an uninterrupted 

 web, but others, as in Corpini Saturn ia make short 

 ends so that the silk cannot be wound off; but science, no 

 doubt, will soon obviate these apparent difficulties, and thus 

 rescue a very large amount of most valuable property from 

 its present useless condition. I wish you particularly to 

 remember the formation of the mouth in the larva ; it is 

 called a mandibulate, from using mandibles in cutting off ita 

 food. 



0S6AXS OF DIGESTION. 



By the aid of these mandibles, or scissors, the larva cuts 

 off its food ; this is then passed into the mouth and down 

 the oesophagus, or gullet, into the stomach ; from here it 

 passes down the rest of the alimentary canal. It receives 

 secretions from the salivary glands, bile ducts, &c., and 

 also from the membranous surfaces of the parts through 

 which it passes ; thus it is acted upon in a somewhat 

 analagous way to the food taken by a higher order of 

 animals. The oesophagus, or gullet, and stomach is very 

 large to receive the immense quantities of food these ever 

 devouring creatures take in. Their periods of rest seem 

 but short, their time being devoted to one object, to eat as 

 much as they can whilst in this transitionary state. To give 

 gome idea of the voracity of larvae. Count Danolo in his 

 history of the silk-worm, states that when first hatched it 

 only weighs one hundred parts of a grain ; in thirty days it 



