110 



THE AMERICAN MONTHLY 



[June, 



The infusorial world, with its count- 

 less number of inhabitants — more 

 numerous than the stars, or the sands 

 of the seas, surround us upon all 

 sides ! They abound in the river, 

 creek, pool, pond and the open sea. 

 Every blade of grass, every flower, 

 the atmosphere we breathe, the food 

 we eat, swarm with them. There is 

 no limit to the diffusion of life where 

 air and moisture exists, fascinating 

 alike the biologist and the young ex- 

 plorer in the study of their forms and 

 habits. Particularly is this the case 

 since the great improvements that 

 have taken place in our optical in- 

 struments, during the last ten years, 

 by means of which the most minute, 

 elementary and beautiful forms of 

 life have been studied. 



Siebold, in 1805, expressed an opi- 

 nion that animalcules consisted of 

 simple cells or vesicles, forming proto- 

 plasmic masses, from which all higher 

 organisms were evolved, and that in 

 turn, the higher passed into the lower 

 forms. Tracing these minute crea- 

 tures through their various changes, 

 brings us to the dim, shadowy line 

 (too subtle, too obscure for positive 

 definition) that separates or blends 

 all animal and vegetable life together. 



A brief history of the more impor- 

 tant epochs of infusorial investiga- 

 tion might be arranged somewhat as 

 follows : The original inventer of the 

 microscope,, or the double convex 

 lenses used as such, cannot be posi- 

 tively identified. These investiga- 

 tions commenced over two hundred 

 years ago, and we are surprised at 

 the results obtained by those early 

 investigators, with the rude appli- 

 ances with which they worked. Out 

 of the use of these simple lenses, 

 through long and tedious processes, 

 was evolved the compound micro- 

 scope. Fontana, of Naples, Drebell, of 

 Germany, and Jansen & Son, of Eng- 

 land, have in turn been credited with 

 the invention, which, in its simplest 

 form, attracted public notice about 

 the year 16 19. Nearly half a century 

 passed before it was regarded as more 



than a toy, until Petrus Borellus, an 

 Italian, made some discoveries among 

 the lower forms of animated life. 

 Then came an Englishman, Dr. Ro- 

 bert Hooke, who, in 1665, wrote his 

 famous " Micrographia Illustrata." 

 A few years later the illustrious 

 Dutchman, Antony Van Leeuwen- 

 hoek, made extensive scientific re- 

 searches in this field, and stimulated 

 others to take up the study. His 

 earliest contributions are found in 

 " Philosophical Transactions " for the 

 year 1677. [Examples of this eminent 

 investigator's descriptions of the curi- 

 ous infusoria he had met with were 

 given, the quaint expressions causing 

 much merriment.] Further investiga- 

 tions were made by some English- 

 men in 1703, confirmatory of what 

 Leeuwenhoek had discovered with 

 his simple apparatus, twenty-five 

 years before. Next, the names of 

 Sir E. King, John Harris and Ste- 

 phen Gray are recorded as those of 

 able contributors and investigators in 

 this respect. 



The very first illustrations of in- 

 fusoria are found in a publication of 

 Sir E. King. John Harris gave the 

 first description of Euglena viridis, 

 and he made some very shrewd ob- 

 servations on their rapid mode of re- 

 production. 



The Doctor next touched upon the 

 very crude, but ingenious contriv- 

 ances that early investigators used in 

 making their remarkable discoveries. 

 In 1703 several of the larger species 

 of infusoria were accurately described 

 and figured by Leeuwenhoek, Wilson 

 and others, Wilson claiming to have 

 constructed a lens that magnified 640 

 diameters. In the earlier half of the 

 eighteenth century contributions to 

 infusorial history were made by Louis 

 Joblot, Henry Baker and Abram 

 Trembly. Joblot, in 17 18, published 

 a treatise on " Microscopes and In- 

 fusoria," in which his imagination 

 played havoc with existing facts. 

 Henry Baker, in 1742, wrote a 

 book, entitled " Microscope Made 

 Easy," which contributed to the stock 



