34 PHILOSOPHICAL TRANSACTIONS. [aNNO 1703 



when thin spread, it dries immediately; so that you must be very quick, with it. 

 I diluted some of the semen with warm water, just so much as would a little 

 change the colour of the water, and by that means could see them more distinct 

 and separate, even with smaller magnifiers, and they then kept their shapes 

 long, even till next day when put in a small tube, but were without motion. 

 To my best glasses they appeared about the size, and in the positions here re- 

 presented, fig. D. 



I have seen in some water, fishes as small as cheese-mites, of different sorts, 

 very curiously made; they are of the crustaceous kind, shelled with many joints 

 with very long horns, fringed tails, and have many legs like shrimps; some of 

 these carry their eggs or spawn under their tails in one bag, another sort in two 

 distinct bags, and some kinds on the fringes of their legs, like lobsters. 



The animalcula in pepper-water, represented in fig. e are very common, and 

 are described by Mr. Leuwenhoeck in some former Transactions. The tails of 

 some of these are Q or 10 times as long as their body, (which is about 4- of a 

 hair's breadth) but generally they are 4 or 5 times as long. As they move, they 

 will often twitch up the tail in the posture as marked at b, and this spring is so 

 strong, as when the tail is entangled, (as commonly it is) by the end, they bring 

 back their whole body by the jerk and convolution of the tail, which then re- 

 turns to its first straightness. To a good glass, the end of the tail seems to have 

 a knob on it as in a, and the folding appears as in b ; but examining it with 

 one of the greatest magnifiers, I found the knob to be only a close spiral revo- 

 lution, like the worm of a bottle-screw, and that the whole tail when twitched 

 up was also a spiral: this appearance, to the great magnifier, is represented in 

 c and d. I have also seen them sometimes as in e. I have farther observed 

 that when these lie still, they thrust out a fringed or bearded mouth, which 

 they can draw in again, and that a rapid stream runs constantly toward their 

 forepart, as if they drew in water; but I rather believe this current is made by 

 a nimble tremulous motion of some minute fins or legs, which my glasses will 

 not show. 



Those animalcula marked r also abound in all the waters, and are the largest 

 of all, and I can see them in a good light and position with the bare eye, their 

 length being about the breadth of a hair. These have a very quick motion, 

 and are pepetually beating about like a spaniel in a field, and by their frequent 

 turns and returns, sudden stops, and casting off, seem to be always hunting for 

 prey. Their bodies are very thin, that which I take to be the back being much 

 darker than the other side, and they frequently turn sometimes one side and 

 sometimes the other towards the eye, and often part of each may be seen. 

 Their edges are as it were fringed, with a multitude of very minute feet, which 



