ce 
232 LEEUWENHOEK AND HIS ‘‘ LITTLE ANIMALS ”’ 
half as long and half as broad as one of the oval blood- 
corpuscles ; all being of one and the same structure. 
‘Twas no small pleasure to see this sight: for I had let 
so much time slip by, that the oval blood-corpuscles were 
sunk down somewhat (owing to their weight) towards the 
bottom, and then these animalcules made a pretty motion, 
for as they went a-swimming, they knocked into the 
blood-corpuscles, and sent them spinning. And I judged 
that in every particle of blood as big as asand-grain there 
were quite 50 animalcules. 
The blood aforesaid was very watery, and not pure 
blood by any means: for as soon as I separated a good 
bit of the frog’s skin from the flesh, some watery juice‘ 
began to run out of the skin, as well as the flesh ; and still 
more when I opened the belly. And as I had well-nigh 
bashed in the frog’s head, trying to make it keep quiet, 
methought some watery juice might well have been 
squashed out of its mouth or stomach too, and from this 
juice the animalcules might have come; for when I 
afterwards took blood out of the frog’s veins clean, I 
could discover no animalcules therein; neither when 
I viewed the watery matter which came from between the 
skin and the flesh, nor yet in that from the hollow of the 
belly.’ 
In the foresaid watery matter, I noticed some irregular 
particles, most of which looked to me round, and were about 
as big as the globules of our blood. In some of these’ I 
could make out that they were composed of 6 lesser 
globules; and there were besides particles that seemed 
only about 4 of the bigness of the others. And when I 
* 4.¢., lymph. 
* From the foregoing and succeeding passages it is clear that L. satisfied 
himself that there were no animalcules in the blood or lymph: and 
consequently there is no foundation for the statement—sometimes made— 
that he discovered protozoa in the blood of the frog. 
* Plasma-cells, from the lymph. The smaller “ globules” inside them 
were doubtless the large basophile granules contained in such cells. 
