TOL. XIII.] PHILOSOPHICAL TRANSACTIONS. SQS 



which are so called xxrU^o^^nv, though the former likewise are round. Nor is 

 there any out of the hody that I know of, that are thus flat. 



The second particular I observed was its joints. From these large incisures 

 of the body, a great number or genus of animals have the name of insects. 

 In earth-worms, leeches, &c. the annuli, which make up the length of the 

 body, are very remarkable; but much different from those in our present sub- 

 ject; those being more proportionate to one another, and not of so unequal a 

 length. And in the teretes and ascarides, the surface of the body seems more 

 even and smooth, and not divided after this manner. These joints are so con- 

 nected, that the lines or extreme edges of the former come over the latter ; 

 which is to be well observed, and may direct us to that part or extreme, where 

 we may suppose the head to be placed. These edges of the former joint, which 

 shoot over the latter, in some I have observed to be plain and smooth ; in others 

 crenated and indented ; in all, by drawing it through one's fingers from the tail 

 to the head, there is found a great roughness ; but if the other way, from the 

 head to the tail, it seems smooth. 



3. Many who have observed this worm, take notice of the difference of its 

 extremes ; how much larger one is than the other ; but not well considering the 

 setting on of the joints, they have often mistaken the head for the tail ; for in 

 all I have hitherto observed, I constantly found that extreme where the head is 

 set on, if we may allow it to have any, much smaller than the other; sometimes 

 not half a quarter so broad ; in others less or greater, often according to the 

 length of the worm ; but in all I take notice, if they are of any considerable 

 length, that the joints towards the head are vastly shorter than towards the 

 tail. For in one I have by me (fig. 1, pi. I9,) 24 feet long, there about live 

 joints make an inch; whereas the latter joints here are above an inch long; but 

 in some I have taken out of dogs, there where 30 or 40, sometimes above 60 

 annuli, which, towards the head, make up but the length of an inch ; whereas 

 towards the tail 6 or 7 joints equalled that measure, and sometimes 3 ; so that 

 gradually the joints seem to increase, both in length and breadth, as they ap- 

 proach the tail. But withal it must be observed, that according to the corru- 

 gation or extension of these joints, their dimensions will be altered; which is 

 most apparent in them when alive. That likewise there is a great difference of 

 these joints in the various species of this worm; for I think there are more sorts 

 than one. And as to the differences of them, there are these I have taken notice 

 of. 1. That in most the joints gradually and very sensibly increase in length. 

 2. In some, those orifices, which I take for mouths, were placed about the 

 middle of the joints, on the edges ; in others, about the middle of the flat of 

 the worm, near the jointings. 3. These juttings, or lips of the upper joints, 

 VOL. II. 4 G 



