LETTER 96. MUSSEL-WATER 213 
creatures may not gobble up another sort, using it as 
food,’ just as we see that big fish do? For, an ’twere 
otherwise, the water would get stuffed full with little 
animalcules. 
One day afterwards I looked at the animalcules again, 
and saw, to my wonder, that many of ’em were coupled; 
nay, some of ’em even coupled before my eye; and at the 
beginning of their copulation they had a wobbling motion, 
but after coupling swam forward together, and did stay 
still too, fixt to the glass.’ 
At this time I saw also that the bodies of each animal- 
cule of the pair were of a roundish figure ; for no matter 
how they turned about in swimming forward, they always 
kept one and the same shape, looking like a little round 
cluster of grapes, the cluster being stuck together very 
tight; and as the animalcules swam forward, you saw each 
of the supposed grapes in motion. 
"Twas eventide when I carried out the observations 
last mentioned; and next day, in the morning, I found 
that many of the animalcules were dead, and by evening 
they were so diminished, that I could find but four of 
them that were still alive: wherefore I concluded, that the 
little creatures were died off for want of food. After 
another night had passed, I saw but one animalcule living ; 
and the bodies of all the dead animalcules in the water 
were so gone to pieces, that I saw nought but little round 
particles (as they seemed to my eye), which made the 
water, wherein these little animals had been swimming, 
all troubled. 
' As the “ bigger sort’ were, in part, ciliates, while the “smallest sort ”’ 
were bacteria, L.'s conjecture here was perfectly sound. 
* This passage proves conclusively that L. observed the conjugation of 
ciliates. In his earlier observations he had only seen the organisms joined 
together; and consequently he may have seen ciliates really undergoing 
fission—not conjugating. But here he says he actually saw them come 
together, so that there can be no doubt as to the correctness of his 
interpretation. 
