660 PHILOSOPHICAL TRANSACTIONS. - rANNOl7l2. 



smaller tubes ; the same to be observed in different distanced planes. I have 

 since repeated the same experiment in vacuo, where, in all respects, it answered 

 as in the open air; which is a plain indication, that the presence of the air has 

 nothing at all to do in producing this phenomenon. 



Additional Observations on the Production of Mites, &c. By Mr. Anthony 

 Fan Leuivenhoeck, F.R.S. N° 333, p. 498. 



I formerly acquainted you how mites couple and lay their eggs, and how 

 young mites are produced from those eggs ; and that I observed the hair on 

 their bodies. Though I then imagined that I had observed every thing about 

 the mite that was to be seen, yet I have thought fit to view one of these ani- 

 malcula again with a microscope; and the rather, because in observing those 

 small animalcula that feed upon the nutmeg, I found that those particles on 

 their bodies, which one would take to be hairs, are not really so ; for I cannot 

 allow those particles to be hair, or wool, unless they are smooth and even, 

 setting aside the bark, or skin of the hair, which may be the cause of its being 

 a little rough and uneven. 



Those 6 or 8 long particles, on the body of the mite, and which one would 

 call hairs, are longest on the upper part of the body, being^wice as long as 

 those on the side : and when one carefully, and through a microscope that 

 magnifies very much, observes those long particles, one would judge that such 

 a long particle consists of 50 parts, which seem to be little joints ; and that 

 from each of those divisions small hairy particles again proceed. I could dis- 

 cover also, that the mites had power to move those long particles, which I 

 formerly took to be hairs, in such a manner, that when they were obliged to 

 creep through narrow passages, they could lay these little hairy particles down 

 close to their bodies; and that these particles had each of them but one moving 

 joint, which was next to that part which was fastened in the skin. 



Thus we see the wonderful formation of that small animal the mite : but 

 what shall we say to the unspeakable number of many kinds and particular 

 forms of other animalcula, some of which are so small, that their whole body 

 is not only not so thick as the diameter of one long particle, which is on the 

 body of the mite, but even not so large as one of the slender particles, on those 

 jointed parts of the long hairy particles; and which animalcula are not to be 

 seen, but through some of the most magnifying microscopes: and if one could 

 see the smallest animalcula so large and so clear, as we see a mite, we should be 

 more surprised I believe at their figures, than we are at that of a mite : in 

 short, the smallness of the parts, of which all bodies are composed and set to- 

 gether, is so very minute, that it is not to be conceived by man. 



