LETTER 122. 2 sanuaRy 1700 257 
home, while I was busy looking at the multifarious very 
little animalcules a-swimming in this water, I saw floating 
in it, and seeming to move of themselves, a great many 
green ' round particles, of the bigness of sand-grains. 
When I brought these little bodies before the micro- 
scope, I saw that they were not simply round, but that 
their outermost membrane was everywhere beset with 
many little projecting particles,” which seemed to me to 
be triangular, with the end tapering to a point: and it 
looked to me as if, in the whole circumference of that 
little ball, eighty such particles were set, all orderly 
arranged and at equal distances from one another; so 
that upon so small a body there did stand a full two 
thousand of the said projecting particles. 
This was for me a pleasant sight, because the little 
bodies aforesaid, how oft soever I looked upon them, 
never lay still; and because too their progression was 
brought about by a rolling motion; and all the more 
because I imagined at first that they were animalcules. 
And the smaller these little bodies were, the greener in 
colour they appeared to me: whereas contrariwise, in 
the biggest (that were as big as a coarse grain of sand) 
no green colour could be made out in their * outermost 
part. 
Each of these little bodies had inclosed within it 5, 6, 7, 
nay, some even 12, very little round slobules,* in structure 
like to the body itself wherein they were contained. 
While I was keeping watch, for a good time, on one of 
the biggest round bodies, among the others, in a little 
water, I noticed that in its outermost part an opening 
' groene ronde deeltjens MS. ronde deeltjens Dutch printed version 
“reat round particles” Phil. Trans. Groene (green) is very important ; 
and “great” is an obvious mistranslation or misprint. The Latin version 
also omits “‘ green ’’—calling them simply particulae rotundae. 
2 ¢e., the individual flagellates composing the colony. 
* het MS. haar printed version. 
* i.e., the daughter-colonies. 
Li 
