588 ' PHILOSOPHICAL TRANSACTIONS. [ANNOI7OI. 



at last, on the 8th of March, I could see the blood in one of the arteries, but 

 could not discover where the circulation began. 



I have often taken up that sort of spider whose breech is much larger and 

 thicker than of others, to see whether I could discover any circulation of the 

 blood, but in vain ; and to satisfy myself, whether they had any globules in 

 their blood, I cut off one of the hinder legs of such a spider, and viewed the 

 blood that ran out, in which I found but very few globules ; but wounding it in 

 the breast, or fore-part of the body, and observing the blood that flowed from 

 thence, I discovered abundance of globules in it ; and cutting off part of the 

 leg of another spider, I found more globules there, though I could not perceive 

 any circulation of the blood in the legs. 



I have often seen a spider hanging down from a branch of a tree by a thread 

 of his own making, and holding fast by one of his hind-legs, which has three 

 particular claws, two of which are at the very end, and each claw is armed with 

 several teeth like saws, which towards the joining with the foot grow narrower 

 ' and closer together, and where the thread it has spun maybe close twisted, 

 just as in a pully, on which the clockmakers put their lines to fasten the weight 

 on, which in the beginning is wide and large, but the longer it grows the 

 narrower it is. 



Fig. 4, pi. 15, ABCDEF represents a small part of the leg of a spider; bcd 

 show the two extreme claws, armed with teeth like saws ; e the third that has 

 no teeth ; which claw I suppose he uses on several accounts ; this is certain, that 

 when the spider does not wind himself by his thread upwards, but runs along 

 his web, then he takes hold of the spun thread with this third claw. The 

 above-mentioned spider is provided with eight long and two short legs ; which 

 last stand out on each side of the head, having such claws as are before-men- 

 tioned. Further, I discovered eight distinct eyes, two of which are on the top 

 of the head, in order to see what passes above him. Below those were two 

 other eyes, to look straight forwards. On each side of the head were two more, 

 close to each other ; the two foremost eyes to see, I suppose, what passed col- 

 laterally before him, the two hindmost to see the same backwards. 



Fig. 3 shows the forepart of the body separated from the membrane or pel 

 licle it lay in ; pa the eyes that look upwards ; kl those that look straight for- 

 wards ; IM those that look sideways forward ; hn those sideways backward. 



Now as the spider's eyes are immoveable, having no muscles belonging to 

 them, it is easy to conceive how necessary 8 eyes are, in order to look round 

 about, the more easily to catch his prey. 



I found that the spider has two instruments or cases for his sting, in the fore- 

 part of his head, which, when he does not use, he places in great order under 



