64 CLASSICS OF MODERN SCIENCE 

 top turn round, the circumference they made being no larger than that 

 of a grain of small sand, and then extending themselves straight for- 

 ward, and by and by lying in a bending posture. I discovered also 

 several other sorts of animals ; these were generally made up of such 

 soft parts, as the former, that they burst asunder as soon as they came 

 to want water. 



May 26, it rained hard; the rain growing less, I caused some of 

 that rain-water running down from the house top, to be gathered in a 

 clean glass, after it had been washed two or three times with water. 

 And in this I observed some few very small living creatures, and 

 seeing them, I thought they might have been produced in the leaded 

 gutters in some water that had remained there before. 



I perceived in pure water, after some days, more of those animals, 

 as also some that were somewhat larger. And I imagine, that many 

 thousands of these little creatures do not equal an ordinary grain of 

 sand in bulk ; and comparing them with a cheese-mite, which may be 

 seen to move with the naked eye, I make the proportion of one of these 

 small water-creatures to a cheese-mite to be like that of a bee to a 

 horse; for, the circumference of one of these little animals in water 

 is not so large as the thickness of a hair in a cheese-mite. 



In another quantity of rain-water, exposed for some days to the 

 air, I observed some thousands of them in a drop of water, which 

 were of the smallest sort that I had seen hitherto. And in some time 

 after I observed, besides the animals already noted, a sort of creatures 

 that were eight times as large, of almost a round figure ; and as those 

 very small animalcula swam gently among each other, moving as 

 gnats do in the air, so did these larger ones move far more swiftly, 

 tumbling round as it were, and then making a sudden downfall. 



In the waters of the river Maese I saw very small creatures of 

 different kinds and colours, and so small, that I could very hardly dis- 

 cern their figures; but the number of them was far less than those 

 found in rain-water. In the water of a very cold well in the autumn, 

 I discovered a very great number of living animals very small, that 

 were exceedingly clear, and a little larger than the smallest I ever 

 saw. In sea-water I observed at first, a little blackish animal, looking 

 as if it had been made up of two globules. This creature had a 

 peculiar motion, resembling the skipping of a flea on white paper, 



