L A Letter to the ^yal Society^ from Mr Anthony 
Van Lceuwcnhock, F. S. concerning Aninnal- 
cnh on the (^ots of ^Hch-weed^ Sec. 
YOa may remember, that in my Letter of the a 5th 
of Decemb. 170a. I affirmed that the Animalcula, 
reprefcnted by Fig. 8. a.b.c. that were faftned to the 
fmall Roots of that Orcen ftufF found on the top of the 
Water in our Ditches and little Canals,which we call Duck- 
wecdsj had two fmall Wheels ifluing out of their Bodies. 
A certain Curious Gentleman, that faw the Motion of 
thefc Wheels with great fatisfaftion, entreated me, that 
wheii I had an opportunity, I would once again (how 
him this Wonderful Rotation. 
In the Month of laft, I caufed feveral of thefe 
Wceds^as they were carried by the Stream thro ourTown, 
be taken out of the Water in an Earthen Pot, and took 
my full vi^w of the foremention'd Aniraalcula at feveral 
times, which appear'd as here in Fig. i. ABCDEFC. 
Tl^e Cafe or Sheath of which is reprefented by A B G, 
into which the Animalculum betakes itfelf, upon the 
|eaft (baking or ftirring of the Duck- weed, and then 
tiirufts itfelf out again as far as BCFG, and at 
the fame time appear the two little Wheels defcribed by 
C DE F, m bbferving the Motion of which one would 
be apt to think they were two real Revolving Wheels. 
But fo (pon as we were able to place the Animalcalum 
before our Eyes, in fiich a pofition that we could Tiew 
'the little WheeK not partially, as is here reprefcnted, 
but compteatly, and all at onc^, wc were convinced of 
our 
