IC THE EOTIFEEA. 



wliool-likc or imlcnted particles moved in a circle, at the same time out of a clear and 

 transparent place a little round particle appeared, which, without nicely viewing, could 

 hardly be perceived ; which particle growing larger, moved with great s\viftness as it 

 were about its own axis, and continued without any alteration in its place, till the 

 aninialcuhnn had drawn part of its body back into its sheath ; in doing which it placed 

 the said round particle on the edge of its sheath, which thus became augmented with a 

 round globule ; and whereas the animalculum had placed the said globule on the east 

 part of its sheath, another time it fixed it on the south or north side ; by which means 

 the sheath was regularly increased on all sides." 



Of course this is but a rough sketch of the machinery and actions of the famous tube- 

 maker ; but it is a vigorous one, and true to the life as far as it goes. 



With equal truth and vigour does Leuwenlioek describe, in the same paper, the 

 transformations of VhUodina roseola ; — that creature, whose powers of lying dormant for 

 rotiferous ages, and of then coming to life again, have made it as famous as the " Seven 

 Sleepers." 



To anyone with a sense of humour it must be delightful to read the following para- 

 graphs of Leuwenhoek's paper ; and then to reflect how his discoveries have been re- 

 peatedly re-discovered ; and how again and again they have been cliallengod, con- 

 firmed, forgotten, and once more discovered. In fact, the Philodine has been the 

 cause of a dispute which has all the marvellous properties of the Eotiferon itself. For it 

 periodically goes to sleep and revives again, just as P. roseola does ; but with a difference. 

 The Eotiferon, when it awakes after its long sleep, takes up its life at the point where it 

 left it off ; and ultimately " gives up its murmuring breath " after an existence of three or 

 four years ; but the dispute concerning it invariably begins again both de novo and de 

 ovo ; and having already lasted, with periodical intermissions, for nearly 200 j-ears, 

 evidently bids fair to last for 200 years more ; as it has only a short time ago awakened 

 once more, as fresh and as vigorous as ever, and found its way into our daily papers. 



" I discovered," says Ijouwcnhoek, " several aiiimakula that protruded two wheels out 

 of the fore-part of their body as they swim, or go on the sides of the glass. . . . This sort 

 I found, in great numbers, in the gutter water which had stagnated some days in the small 

 pits or ca\-ities of the lead. ... In October 1702, I caused the dirt of the gutters, when 

 quite dry, to be gathered together, and taking a small quantity of it, I put it into a paper 

 on my desk ; since which time I have often taken a little of it, and poured on it boiled 

 water after it had stood still till it was cold, that I might ob\-iate any objection that 

 should bo made, as if there were living creatures in that water. These animalcula, when 

 the water runs off or dries away, contract their bodies into a globular or oval figure. . . . 

 In the month of September I put a groat many of the last-mentioned animalcula into a 

 wide glass tube, which presently placed themselves on the sides of the glass ; whereupon, 

 pouring off the water, I then observed that several of the animalcula, to the number of 

 eighteen or nineteen, lay by each other in a space of coarse sand; all of which, when 

 there remahied no more water, closed themselves up in a globular figure. Some of these 

 animalcula were so strongly dried up that one could see the wrinkles in them, and they were 

 of a reddish colour ; a few others were so transparent, as if they had been little glass 

 balls, that, if you held them up between your eye and the light, you might move your 

 lingers behind them, and see the motion through their bodies. After these animalcula 

 had lain thus dried up a day or two, in an oval or globular form, I poured some water 

 into the glass tube ; whereupon they presently sank to the bottom, and after the space of 

 about half an hour began to open and extend their bodies, and, getting clear of the glass, 

 to swim about the water. . . . Li the month of October, before the dirt of the leaden 

 gutter was quite dried up, I took a handful of it, and laid it on a glazed earthen dish in 

 order to preserve it. . . . Upwards of twenty-one months after, I took some of this dry 

 stuff and infused it, both in cold water that had been boiled, and in rain water newly 

 fallen ; whereupon the animals began to show themselves in great numbers." 



The only points of this much vexed qiiestion that Leuwenlioek passes over are : 



