42(3 PHILOSOPHICAL TRANSACTIONS. [aNNO 1730. 



ward : the sucker being fastened, it bends itself circularly again to bring the 

 protuberance up to it, and apply it as before. By this the worm prolongs itself 

 to apply its sucker, and contracts itself to do the same with its protuberance. 

 Thus these motions and applications are made successively, and as often as 

 there is occasion. The hinder part fastens itself to nothing, but is always drawn 

 by the part which goes before it. 



This little animal did not live above 2 hours after it was taken out of the 

 place where found. It became languid as soon as it was exposed to the air, and 

 recovered some vivacity as soon as put into a little sea-water, sending out from 

 its mouth a little green, almost imperceptible thread, which kept itself sus- 

 pended in the water, and was about as long as its body, and was as fine as the 

 finest thread of a spider's web. After this thread was put forth, it emitted also 

 from the same place some little bubbles of air. The body of the worm de- 

 creased in bulk gradually as long as it lived, and after its death this diminution 

 either ceased, or became less sensible. Having cut its belly through with a pair 

 of scissars, as soon as it was dead, and squeezed it, there came out a black, 

 thick liquor. 



From these facts we can draw but very slender consequences. It is certain 

 that this insect cannot live out of the water; so that we cannot imagine it could 

 live in the stomach of any land-animals, unless they came near the nature of 

 the amphibious; for the worms which grow on, or within the bodies of animals, 

 ought to be of the same nature with them, with regard to the elements in 

 which they live. This worm seems to be incapable of living any where but in 

 the bodies of fish, seeing it kept alive but a very little time in the sea-water in 

 which it was put, having been exposed to the air but one moment at two differ- 

 ent times ; which was not sufficient to alter its parts, and cause its sudden 

 death. The almost immediate diminution of its bulk in the water is another 

 mark that it cannot live in the sea out of the body of the same fish ; for if the 

 water, which was more natural to it than the air, was injurious to it, much 

 more would the air have been prejudicial. The fine fibre which it put forth, 

 and the decrease of its size, were signs that it suffered some uneasiness. The 

 black and thickish juice, which came out of its entrails, could be nothing but 

 some half coagulated blood, which it had sucked in the stomach of the fish. 



As the bonite is a fish of prey, living on other smaller fishes, it is probable 

 that this little leech usually fastens itself on those which come into the stomach, 

 and that it lives on their blood. The stomach, in which it was found, was 

 quite empty; so that it was probably as hungry as the bonite could be; for this 

 fish is not easy to be catched but when hungry. However, it was the first 

 time he found it so very empty, though he had seen a great number opened. 



