( 52 ) 



mal appeared to be leafl advanced, \vhereas before this I Iiad opened 

 the mod perfect ones : and thefe I found in the fame forwardnefs of 

 growth as the eggs I had opened on the 20th of May, and by this 

 time ail the dark coloured bodies of the animals, efpecially the head, 

 miglit plainly be difccrned tln-ough the tranfparent fliell. 



This rapid formation of the Silk-worm, and its motion within the 

 egg, excited in me the greatefi: admiration, and if I had not profe- 

 cuted tlie obfervations I have been relating, I fliould have thought 

 it abfolutely impofllble : for, in the preceding autumn, I had placed 

 thefe eggs in a much greater degree of heat than they were now ex- 

 pofed to, and yet I could not at that time promote the perfed forma- 

 tion of tlie animals within them. And, from my prefent obferva- 

 tions, I was led to conclude that it has been an eOi^ntial propert}^ of 

 this creature, implanted in its Ipecies at the firft creation, that the 

 vital principle mull lie fhut up in the egg for more than the fpace of 

 fix months, without any augmentation of its fubftance, except in the 

 formation of that part which is to ferve firft for the defence and pre- 

 fervation, and afterwards for the nourifliment and increafe of the 

 animal, and this is the membrane or fkin I have before defcribed ; and 

 that were it not for this provifion made by nature, the whole fpccies 

 of the Silk-worm would be liable to pcrifli in one year : for if a warm 

 i'eafon in autumn fliould caufe the worms to be excluded from tlie 

 eggs, the fucceeding cold and rains muft prove their deftrudtion. 



I obferved that the Silk- worms always came forth from their eggs 

 in the morning, and not in the afternoon. To afcertain this, on the 

 laft day of May, in the evening, I counted the eggs I had then left, 

 which I found to be about two hundred. The next day, namely, on 

 the firft of .lune, at fix in the morning, ninet} -feven Silk- worms had 

 come out of their eggs, and the fame day at dinner-time, or about 

 one o'clock, thirty-two more. In all the afternoon, althougli the 

 atmoJ'phcre was warm, only one made its appearance ; but the next 



