HENRY BAKER, 1742, 1753. 13 



"Oct. 6th, 1702. I thought those which I called capillary eels had been 

 peculiar to pepper-water, but have since observed the same (tho' but few) in some 

 standing water which drained from an horse dunghill. Among these the prettiest 

 object was a great number of a kind of eels which appear most distinctly when the 

 water is almost dry, which make brisk shoots, and have a pretty wriggling motion ; 

 they are of different lengths, and are about the thickness of what I^call capillary 

 eels." 



Among the contributors to our knowledge of infusorial life during the 

 earlier half of the eighteenth century the names of Louis Joblot, Henry 

 Baker, and Abraham Trembley hold a p: eminent position. Joblot, author 

 in the year 1718 of a large treatise upon microscopes and the forms 

 of microscopic animals to be found in various artificial infusions, was 

 unfortunately led, through his possession of a more than ordinarily romantic 

 imagination, to embellish very considerably his descriptions and drawings 

 of the various types observed, these latter being in many instances moulded 

 by his facile pen into the similitude of satyrs' heads, and other monstrosities 

 having no existence in the plain and solid ground of fact. Henry Baker's 

 work, 'The Microscope Made Easy,' published in the year 1742, while 

 embracing a general account of all the various forms of microscopes in use 

 up to that date, and of subjects suitable for examination with the aid of 

 that instrument, includes in addition, a description with figures of many 

 forms of animalcules discovered by himself in organic infusions. This 

 special subject is, however, treated still more extensively in his subsequent 

 volume, 'Employment for the Microscope,' published in the year 1753. 

 In this last-named treatise is to be found the first printed account, accom- 

 panied by an easily recognizable figure, of the species now well known 

 by the title of the Swan Animalcule, Lacrymaria olor, and upon which 

 Mr. Baker conferred the name of the " Proteus." Of this he writes : 



" Having one evening been examining of the slime-like matter taken from the side 

 of a glass jar, in which small fishes, water-snails, and other creatures had been kept 

 alive two or three months, by giving them fresh water frequently, I was diverted with 

 the sudden appearance of a little creature whose figure was entirely new to me, 

 moving about with great agility, and having so much seeming intention in all its 

 motions, that my eyes were immediately fixed upon it with admiration. Its body 

 in substance and colour resembled a snail's ; the shape thereof was somewhat ellip- 

 tical, but pointed at one end, whilst from the other a long, slender and finely pro- 

 portioned neck stretched itself out, and was terminated with what I judged to be an 

 head, of a size perfectly suitable to the other parts of the animal. In short, without 

 the least fancy, which is ever carefully to be guarded against in the use of the 

 microscope, the head and neck, and indeed the whole appearance of the animal, 

 had no little resemblance to that of a swan : With this difference, however, that its 

 neck was never raised above the water, as the neck of a swan is, but extended 

 forwards, or moved from side to side, either upon the surface of the water, or in a 

 plane nearly parallel to the surface thereof. It swam to and fro with great vivacity, 

 but stopped now and then for a minute or two, during which time its long neck 

 was usually employed, as far as it could reach, forwards, and on every side, with a 

 somewhat slow but equable motion, like that of a snake, frequently extending thrice 

 the length of its body, and seemingly in search of food. I could discern no eyes, 

 nor any opening like a mouth in what appears to be the head ; but its actions 

 plainly prove it an animal that can see ; for notwithstanding multitudes of different 



