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and round bodies four times folded or doubled together, which I took 

 out of the animal's body. Thefe parts were almolt twice the length 

 of the Silk-worm, and at one end, the fituation of which I conceived 

 WHS in the head, they terminated in a point, and fometimes I faw 

 ilTue from this pointed end, an excefnvcly flender thread, four times 

 the length of the Silk-worm. 



Thefe organs, or rather veflels, in the thickeft parts of them, were 

 of a red colour, yet when examined by the microfcope they feemed 

 yellow ; but when I feparated tlie inner from the external part of 

 them, the exterior part feen by the naked eye appeared of a perfe6t 

 yellow. 



Fig. 31, LMN, fliews one of thefe bodies or parts which I have 

 beenjuftdefcribing, and of the lame fize it appeared to the naked eye 

 when dry and contracted. The letters M and N denote how far the 

 red colour extended ; from L to M was of a perfeft yellow, and 

 here I judged that the thread when produced from the interior part 

 of the animal's body was kept ready for ufe. At N is the fmall end, 

 the fituation of which was near the head, and indeed within the head 

 itfelf. Bet\\een L and O, in my judgment, is the way or paflage 

 tlu'ough which is conveyed tlie matter or fubftance of which the 

 threads are compofed. This part was of a yellow colour, and is 

 longer than here pi6lured, being broken ofFat O. Another part or 

 organ of the fame make and fliape, was alfo contained in the Silk- 

 worm's body, and from thefe two parts the fubftance is fupplied for 

 producing the two diftincl threads I have been defcribing. 



Sometimes when this part or organ was broken oft" at N, I per- 

 ceived in it a kind of cavity, but extremely minute. 



I oftentimes took hold of the end of the thread which the Silk-worm 

 Avas preparing to fpin, and drew it out from the body with fo much 

 rapidity, as by twenty- live times to exceed the fwifteft motion of tlie 

 worm in its own Ipinning ; and I found that when the thread was 

 drawn forth to the length of about fifteen or ftxteen inches, it broke 



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