SIfi E. KING, 1693. JOHN HARRIS, 1696. 9 



beings, and which, while not entirely accepted by Leeuwenhoek, is conceived 

 and tossed by him as a very apple of discord to posterity.* 



The period intervening between this first discovery of the Infusoria by 

 Leeuwenhoek, and his further contribution to the literature of the same 

 subject in the year 1703, is signalized by the corroboration of that autho- 

 rity's observations, and an extension of our knowledge of the group, at the 

 hands of several of our own countrymen, among whom have to be more 

 especially mentioned the names of Sir E. King, John Harris, and Stephen 

 Gray. In each case the results obtained by these early investigators are 

 recorded in the pages of the ' Philosophical Transactions,' and in connec- 

 tion with one contribution, that of Sir E. King, is to be found the first 

 published illustration of infusorial life. The form thus represented was 

 obtained in an infusion of pepper, and appears to be identical with the 

 Enchclys arcuata of Ehrenberg. This authority also places on record the 

 results of the experimental application of certain chemical and other sub- 

 stances to living animalcules, a subject which will be found referred to 

 at greater length in the section devoted to this special topic. The account 

 of John Harris's investigations contained in the ' Philosophical Transac- 

 tions ' for the year 1696, embodies the earliest description given of Euglena 

 I'iridis, and some remarkably shrewd and philosophic speculations as to the 

 manner in which Infusoria were so rapidly and unaccountably developed. 

 These latter were altogether opposed to the then newly-conceived theory of 

 spontaneous generation, and, as hereafter shown, add their weight to the 

 evidence which has been since adduced in a similar direction. Mr. Harris's 

 description of Euglena and certain other associated forms, that first men- 

 tioned being evidently a species of Anguillula, and the second a Rotifer, 

 probably R. vulgaris, is as follows : 



" On July yth, 1694, I examined a small drop of rain-water that had stood in a 

 gally-pot in my window for about two months. In the thick part of the drop for 

 the water from whence I took it had contracted a thickish skum I found two sorts 

 of animals as a kind of eels like those in vinegar. I saw here also an animal like a 

 large maggot, which would contract itself up into a spherical figure, and then stretch 

 itself out again ; the end of the last appeared with a forceps like that of an earwig ; 

 and I could plainly see it open and shut its mouth, from whence air-bubbles would 

 frequently be discharged. Of these I could number about four or five, and they 

 seemed to be busie with their mouths as if in feeding. April 27th, 1696. With a 

 much better microscope I examined some rain-water that had stood uncovered a 

 pretty while, but had not contracted any such thick and discoloured a skum as that 

 before mentioned had. A little thin white skum, that like grease began to appear on 



* In association with the discoveries of Leeuwenhoek here recorded, it is worthy of remark that 

 a cabinet of the microscopes, to the number of twenty-six, as self-constructed and employed by that 

 investigator, and consisting of simple doubly convex lenses, were originally presented by him to the 

 Royal Society of England, but have long since been lost sight of. The latebt tidings of them would 

 appear to be furnished by Mr. Henry Baker, who in his work, 'The Microscope Made Easy,' pub- 

 lished in the year 1 785, attests to having had these glasses under examination away from the Society's 

 premises and at his own private icsidence. The recovery of such precious heirlooms, and the recon- 

 signment of the same to their former custody, or among the series of optical instruments belonging 

 to the Royal Microscopical Society, where perhaps they would be even more highly prized, is a 

 consummation most devoutly to be wished, and may possibly be helped forward by this notice. 



