VOL. XLIX.] PHILOSOPHICAL TBANSACTIONS. 6l7 



pipe, and its branches, loaded with small taper worms* of about 2 inches long, 

 which were crawling about, though the animal had been dead many hours ; and 

 the farmer assured him that they always found these worms in this distemper, 

 and knew of no method of cure. Dr. N. had great hopes however, that fumi- 

 gations, either with mercurials, as cinnabar, or with fetids, as tobacco, properly 

 used, might prove of great service. 



XL. On some Remarkable Insects of the Polype Kind, found in the Water ; near 

 Brussels in Flanders. By T. Brady, M.D. p. 248. 



The draught of the plant sent is found in summer-time, in all sorts of ditch 

 or stagnant waters : its colour is white, and its transparent body, when seen with 

 the naked eye, is in length between one and a half and two lines ; but when 

 viewed with a good microscope, whose focus is about 8 lines, it appears as in 

 pi. 15, tig. 1, with leaves,-^- branches, and fruit, and indued with such sensibility 

 that at the least noise made in the room, or on any thing touching the table 

 where the microscope stands, or the water in which it lies, it contracts itself 

 with such activity and swiftness that the eye cannot follow it in that motion, 

 till it reduces itself into the shape in fig. 2. The extension or dilation goes 

 slower, and requires about half a minute before it comes to the form in fig. 5. 

 It can live in its own standing-water for 8 or 10 days, and then looks as in fig. 6, 

 as most trees do in winter-time. It is remarkable that the leaves, which are 

 like bells, live some time after they fall, and retain that faculty of contraction 

 and dilatation ; and when viewed with the great magnifier, whose focus is about 

 2 lines, it appears as in fig. 4. The trunk is as in fig. 3. The number of its 

 branches are undetermined, but commonly found to be between Q and 1 2. He 

 had not tried if it did not regenerate, when cut like polypes : but he could 

 see a vast difference between it and the polype a bouquet, mentioned by Trem- 

 bley.;}: The other curious insect, represented in fig. 7, is found in the same 

 standing-waters with the plant, and is seen with the naked eye, like a little fiat 

 round leaf, whose diameter is about one line and a half ; but when put in a 

 microscope, it shows a circle surrounded with crowned heads, tied by small thin 

 tails to a common centre, whence they advance towards the circumference, 

 where they turn like a wheel, with a great deal of vivacity and swiftness, till 

 they cause a kind of a vortex, in which are seen all smaller insects or bodies 

 either attracted or driven, which probably serve as nourishment for those little 

 crowned things, which in all appearance are, as well as the plant, a sort of 

 insects of prey, that live on smaller creatures. When one of those little heads 



* These worms belong probably to the species of ascaris called ascaris vituli. Linn. Gu el. 

 + Vorticella anasiatica. Linn. t Vorticella socialis. Linn. Gmel, 



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