ANTHONY VAN LEEUWENHOECK 65 

 so that it might very well be called a water-flea; but it was far less 

 than the eye of that little animal, which Dr. Swammerdam calls the 

 water-flea. I also discovered little creatures therein that were clear, 

 of the same size with the former animal, but of an oval figure, having 

 a serpentine motion. I further noticed a third sort, which were very 

 slow in their motion ; their body was of a mouse colour, clear toward 

 the oval point ; and before the head and behind the body there stood 

 out a sharp little point angle-wise. This sort was a little larger. 

 But there was yet a fourth somewhat longer than oval. Yet of all 

 these sorts there were but a few of each. Some days after viewing 

 this water, I saw 100 where before I had seen but one ; but these were 

 of another figure, and not only less, but they were also very clear, 

 and of an oblong oval figure, only with this difference, that their 

 heads ended sharper; and although they were a thousand times 

 smaller than a small grain of sand, yet when they lay out of the water 

 in a dry place, they burst in pieces and spread into three or four very 

 little globules, and into some aqueous matter, without any other parts 

 appearing in them. 



Having put about one-third of an ounce of whole pepper in water, 

 and it having lain about three weeks in the water, to which I had twice 

 added some snow-water, the other water being in great part exhaled ; 

 I discerned in it with great surprise an incredible number of little 

 animals, of divers kinds, and among the rest, some that were three 

 or four times as long as broad ; but their whole thickness did not much 

 exceed the hair of a louse. They had a very pretty motion, often 

 tumbling about and sideways; and when the water was let to run 

 off from them, they turned round like a top; at first their body 

 changed into an oval, and afterwards, when the circular motion 

 ceased, they returned to their former length. The second sort of 

 creatures discovered in this water, were of a perfect oval figure, and 

 they had no less pleasing or nimble a motion than the former ; and 

 these were in far greater numbers. There was a third sort, which 

 exceeded the two former in number, and these had tails like those 

 I had formerly observed in rain-water. The fourth sort, which moved 

 through the three former sorts, were incredibly small, so that I 

 judged, that if 100 of them lay one by another, they would not equal 

 the length of a grain of coarse sand ; and according to this estimate. 



