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1494

1. Two Letters from a Geltleman in the Country, relating to Mr Leuwenhoeck's Letter in Tranfaction, No. 283. Communicated by Mr C.

June 21

Dear Sir,

YOurs of the 10th inftant found me at W. where I alfo met the Tranfact. No. 283. which you felt laft. Finding fomething in it from MrLeeuwenhoeck I greedily run it over, and muft own that I was a little mortified to fee in it an account of a Creature which I thought I had a fort of Propriety in, and of which I had made a Draught, with a defign to prefent you and Mr C. with a rarity, which I believed nobody had met with but my felf. Hoewver,Mr L.'s Picture of it being fo fmall, I thought my Sketches would not be unacceptable, becaufe they not only confirm his account, but may contribute to give you a more perfect Idea of fo odd an Animal : I found it the beginning of this Month in fome clear Water, which I took up in a Ditch at W. in which, with my utmoft attention, I could difcover no more than this one of the fame kind. Fig. I. reprefents it in one of the poftures it appear'd the firft day (for it varies every moment) and the knob at a, which lookt like the Gut caecum, was fometimes a little more lengthen'd ; two days after I could perceive two or three white Fibres at the end of it, and on the fourth day, the Animal lying ftretch'd at its full length, appear'd as in Fig. II. and I plainfly faw, that what I thought an excrefcence was a young one, with 6 horns coming out of the fide of the old one, and the

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(1495)

next day I found it in the Water entirely feparated from the body, and was about one third of the length of the Parent. The formation of the horns are well figur'd by Mr L. and they iffue (like radij) not from the extremity, but quite round a fmall knob, which I take to be the Head. The Horns have a vermicular motion, and are extended or fhorten'd both altogether and feverally. The other end is flat at the extremity, and he often fix'd it (like a Leech) to the bottom or fide of the Glafs in which I kept him. He alfo contracts and dilates his body at pleafure, and efpecially, when touch'd or difturb'd, will bring both Body and Horns into a fmall compafs, and has then the appearance of Fig. 3, and 4. The Horns are perfectly white, and the Body yellowifh, and to a naked Eye not eafily difcernable in the Water, it being when extended no thicker than a good Horfe-hair.

The fmall Plant mention'd in the fame Tranfact is the Lens Paluftris or Duck-meat , which floats plentifully on our Ponds or Ditches. But I muft diffent from Mr L. where he fays it does nto come originally from the bottom, for I very well remember that many years finee, the late W. Ch. Efq; fhew'd me the manner of its fpringing out of the Mud ; and we often obferv'd, that when the Leaves were grown to a competent fize, the force of the Water eafily drew the minute fingle fibr'd Root, and rais'd the Plant to the furface. I own that the Leaves when floating do continue to grow, and may be encreas'd after the manner he mentions, and I have often taken the young Plant which he pictures out of them. fo that they may be call'd Seeds more properly than Leaves; and my opinion is, that toward the end of the year, upon their corruption they fink to the bottom, and there take root, fo as to continue the fucceffion.

The Animalcula which Mr L. defcribes fricking to the Root of the Plant I have often obferv'd not only in Water Plants, but adhering to the bodies of may forts of

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(1496)

Water Infects, which I have feen cover'd almoft all over with Tufts of them, each Tuft being made up of many Animalcula, which appear not much unlike to the Flowers of a Lilly or Fox-Glove.

This Congeries of Animalcula will lengthen and contraft themfelves both altogether and feverally and I have obferved them, when they lye at length, to put out fome wonderfully minute Organs like fmall Feet (not eafily difcern'd even with my belft Glaffes) which by their quick agitation bring a current of Water from all fides toward them. But I was never fo fortunate as to fee that motion in them, which he fays is like that of a Mill wheel ; nor indeed can I perceive the poffibility of fuch a Rotation of any Member in an Animal mechanifm. But I think I can eafily account for this miftake of Mr L. or rather of his Painter; for in the fame Water wherein I have feen thefe Plants and Animalcula, I have obferved a fmall round Creature, whofe many Legs ftand like radij all bout its Body. This has a fwift progreffive motion, but will very often lye ftill (when only you can perceive thofe radij) and then turn very friftly round like a Wheel, fometimes one way, and then ftop and turn the other way, without ftiffing an hairs breadth forward. Now 'tis very probable that one of thefe might fhew its tricks fo very near to, or among a Tuft of the other fix'd Animalcula, that it might be very well taken for part of the fame, and I am very confident this is matter of Fact.

Thefe Animalcula are fometimes feen loofe, but generally, they are fix'd in clufters by their Tails to other Bodies, and perhaps cannot feparate themfelves; and I think it no mean inftance of Providence, that many kinds of Water Infects which are fo fix'd, and even fome of which have but flow and irregular motions, are furnifhed with fuch Organs about their Head, the vibrrion of which, brings a conftant current towards their Mouths, and with that, Food for their Support, otherwife they would be ftarv'd for want of Nourifhment.

If

(1497)

If you ask what Insects those are, on whose Bodies I have seen these Animalcula, I muft tell you they are of divers sorts, and that I have obferv'd no fmall variety in the water of our Ditches, not only of reptiles, and the Catterpillar kind, but of Eeles and perfect Shell-fifh, both Crustaceous and Testaceous, and have been so pleas'd with the Beauty of some of them, that I have kept them many weeks by me, as an agreeable entertainment for such as are curious; and farther design'd, if I could have met with a good hand in the Country, to have got some Figures of then, which I had attempted my self, but with no satisfaction. However, having preserv'd two tolerable Scetches of two sorts of the Crustaceous kind, I venture to send them you, since (tho much to the disadvantage of their Beauty) they will give you a better notion of them than any thing I can write. Fig. V. and VI. shews them as they lye with their back towards you in a swimming posture, but the Members and Legs on the other side are so various, and so much more curiously form'd than those of Lobsters and Shrimps, that I despair of giving any tolerable representation of them in any other position. These are about the same size, the biggest being rather less than a very small Flea, and the least a little bigger than a Mite, but all are Breeders, and carry their Spawn at their Tayl, that of Fig. 5. in two Bags (one on each side) which are fasten'd about the 5th joynt, and the other in a single Bag or Film under the Tayl, and I have often seen these Bags broken, and the Spawn (which is globular and large in the proportion to the Fish) scatter d through the Water. There is also among these a third sort of the same kind, not less elegant, tho far less in bulk, which is shap'd more like a Shrimp, and carries its Spawn like that, but I could never make any Figure of it worth preserving; one thing I had like to have forgot which is very remarkable, that all these three species (as also some other Water Insects) are certainly mon culous, and have their Eye exactly in the middle of their head, X x x x x x x x

head, and I could never with my utmost application find so much as a dividing Line in it. Some of them, especially from Waters, are dark and cloudy, but they are generally so transparent, that through the Shell I can see the peritalitick motion quite through their whole length, and a constant pulsation of a part, wich I guess is the Heart, but I could never discover any course of Blood in them (nor even in Shrimps themselves which are as large as some thousands of these) tho I have seen it plainly in Creatures a little bigger, viz. the smallest new hatch'd Spyders, and in the Water insect which is describ'd and pictur'd (tho not accurately) by Swammerdam, under the (very improper) name of Pulex aquaticus. B ut this is of the Testacerous kind, of which I have seen a greater variety (and not less curious) than of the Crustatcers; but 'tis too late to call a new Caufe.

July 5, 1703 Dear Sir, Snce my last, I have farther observ'd the Lens palustris, and am fully satisfy'd of the truth of its first springing from the bottom. I lately took up some on the shallow side of a Pond, and found the ends of the Stalks (most of which were at least 5 inces long, and as thick as a strong Horse-hair) manifestly radicated in the bottom, so that I could not take them up without railing the Mud with them, which also adhered very visibly to them. These Stalks or Roots are of a curious texture, and almost trasparent, and I have seen their outside very prettily cover'd with a regular sort of Net-work. The Draught in the Transact. No 283 is stiff, and ill represents them.

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