244 THE AMEKICAN MONTHLY [November, 



many particular long particles, and mostly with little figures like flow- 

 ers, as thev are represented in the 8th fig. between k and /. This is 

 the first representation of a diatom I know of. 



In the Philosophical Transactions, No. 384, for March and April, 

 1703, is " an extract from some letters sent to Sir C. H., relating to some 

 microscopical observations communicated by Sir C. H. to the pub- 

 lisher." In the letter of vSept. 29, 1702, he says, " the end of last wxek 

 a buck, which by mischance had his leg broke, was kill'd, tho' so late 

 in the season, and it being rutting time I thought I might, with the 

 greatest advantage, observe the semen masculum. Not to trouble you 

 with some former attempts of this kind, as soon as he was killed I took 

 out one of the testicles with the adjoining setninal vessels^ and found 

 the vasa defer eiitia very turgid and full of a milky fluid. After vari- 

 ous methods of viewing this liquor, I saw the animalca (in prodigious 

 numbers) very perfectly in several postures, moving very briskly, and 

 shew'd them to others, who own'd the}' appear'd as plain as tadpoles 

 to a naked eye." He figures these spermatozoa with globular heads 

 and short tails. 



He figures the vorticella^ which Leewenhoeck figures, but larger and 

 plainer, showing that he had high-power lenses, which were 

 made for him by Mr. Wilson. He also figures various other animal- 

 cules. 



In the Philosophical Transactions for vSeptember and October, 1702, 

 at page 1241, is " The Description and Manner of using a late invented 

 set of small Pocket Microscropes, made by Jam.es Wilson, which, with 

 great ease are apply'd in viewing opaque, transparent, and liquid ob- 

 jects, as the farina of the flowers of jjlants, etc. The animalcula •' in 

 semine, etc." In this he describes and figures the microscope 

 of, eight separate *•• magnifying glasses," in which he follows 

 the " authority of the excellent Dr. Ilook," who " assures us that single 

 magnifying glasses (when thev can be used) are preferable to micro- 

 scopes composed of two or more magnifying glasses." He also figures 

 the down from a butterfly's wing, the '' farina " of maloe, tail of a 

 fish with the veins and arteries in it, two animalcules on the tail of the 

 fish, and " one of the lice found on the beetle, called Scarabens -pedicu- 

 losus.'^ 



But to return to the '• gentleman in the country." He mentions the 

 small plant as figured by Leewenhoeck as " Lens palustris or Duck 

 meat, which is Lemna," and " the Animatc^tla, which Mr. L. describes 

 sticking to the root of the plant," which is Hydra fusca, but says he 

 " was never so fortunate as to see that motion in them, which he says 

 is like that of a mill-wheel." '-But I think I can easily account for this 

 mistake of Mr. L., or rather of his painter, for in the same water 

 wherein I have seen these plants and animalcula^ I have observed 

 a small, round creature, whose many legs stand like radii all about 

 its body. This has a swift, progressive motion, but will often lie still 

 (when only you can perceive those radii'), and then turn vei'y swiftly 

 round like a v^^heel, sometimes one way, and then stop and turn the 

 other way, without stirring an hair's breadth forwards. Now, 'tis 

 very probable that one of these' might show its tricks so very near or 

 among a tuft of th>. ^ther fixed Animalcula, that it might be very well 

 taken for part of the same, and I am very confident that this is a matter 



