210 PHILOSOPHICAL TRANSACTIONS. [aNNO 1 697 . 



goose quill, and all along beset with a great number of little valves ; some of 

 which make a perfect circle with a hole in the middle, and others a half moon ; 

 some are shaped spiral-wise, and of these there is a great one near the tail, 

 fashioned like a heart, which leaves only a very little hole, near which is found 

 much yellow fat, which fills all the cavity of the intestine to half an inch. 

 Two small intestines or appendices, each half an inch in length, and as thick 

 as the feather of a little bird's wing, open into the great gut, and are shut at 

 the other end ; all this structure shows why the intestine, which makes no con- 

 volutions, and yet reserves usually only liquid aliments, does yet retain them 

 to a perfect concoction. 



There is a nerve, the size of a horse hair, all black, hard to break, having 

 knots at intervals, which begins at the mouth of the animal, and passes over 

 the parts that serve for generation in the male. It is fastened in a straight line 

 all along the gut above, terminates at the little circle in the end of the tail, 

 and in its way sends out branches to the right and left side, from every knot. 

 It is very probable, that by this canal, the animal spirits run abundantly, which 

 give so great briskness to this reptile, which cause it to swim so swiftly, and 

 suck with such greediness. 



The leech is hermaphrodite ; the parts of the male destined for generation, 

 are placed where the neck ought to be. The yard, which is about 2 inches 

 long, is white, round, hollow, and gristly ; a part of the yard, which is always 

 in the body, is a sheath about 1 5 lines of an inch in length, as thick as a little 

 bird's quill, covered with a fine membrane, which fastens it strongly to the 

 belly, round about a small hole given the leech for exerting its penis at plea- 

 sure, and not for breathing, as the ancients thought. The other part of the 

 yard, which comes out 9 or 10 lines of an inch, is the size of a sewing thread, 

 and its extremity, for the length of 2 lines, is thicker than the rest. All the 

 yard is hollow, and has in its cavity a white muscle as thick as a hair, fastened 

 only to the root and head, all the rest being at liberty. It is with this muscle 

 that the animal draws the yard into its sheath, which may be tried by cutting 

 it at the root, and drawing out this muscle. 



On every side of the root of the yard there is a little white web, flat, oval, 

 about 2 or 3 lines long, resembling small guts twisted about, with a cartilaginous 

 body, as large as a double thread, and 2 lines long, which fastens to the root 

 of the yard, in which it is probable it carries the prolific matter. A little 

 above the root of the yard, between these two webs, there is a little gristly globule, 

 2 lines long, white, hard, hollow, round, oval, sharp, inwardly covered with 

 a membrane wrinkled and full of a milky liquor. At the head of this globule 

 is a small web, like an epididymis, whose little canal, of the same piece with it, 

 creeps over the globule, and is fastened at the point of it, and above the epidi- 



