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solid and nutritive food, so they are the only suitable 

 food for the silkworms of a more advanced age. 



Leaves of a crude and watery consistence, like wet 

 leaves, are sour, and occasion disease ; leaves which 

 contain more nourishment, grown in the sun, being 

 alone the more suitable. The best quality of leaves 

 are produced, (as it is generally admitted) in dry sea- 

 sons, and on dry soils, and particularly on trees little 

 advanced in growth. 



In our State, the whole summer season is continually 

 dry, and being entirely without rain, most all of our 

 soils are dry ; this is why our leaves are of the first 

 quality for the worms. 



In the early or first ages of the silkworms the amount 

 of food consumed is very small ; but the amount is 

 very great in the last age, as their dimensions and bulk 

 are wonderfully increased. 



If the longitudinal dimensions of the insect be com- 

 pared during the different ages, and their length at 

 hatching being unit, or one, then at the end of the sec- 

 ond age, six ; at the end of the third age, twelve ; at 

 the end of the fourth age, twenty ; at the end of the 

 fifth age, forty. 



I have shown before that the duration of the insect 

 is prolonged by cold, or for want of proper feeding ; 

 while on the contrary, the vital functions of the worms 

 are accelerated by warmth, and also by the degree of 

 attention which is bestowed on them. 



To show that their life is prolonged, when not prop- 

 erly fed, a very remarkable fact occurred here last 



