4 EHRES BERG'S MISTAKES, 



the Infusoria, was beguiled into more errors of the kind above 

 alluded to than almost any other observer. In his great work, 

 " Die Infusionsthierchen," published in 1833, and which, with all 

 its imperfections, is undoubtedly a splendid monument of his 

 industry and genius, there are perhaps a greater number of as- 

 sumed discoveries which no subsequent observer has ever been 

 able to confirm, and a greater number of inferences which are 

 now discarded, although deduced from acknowledged phenomena, 

 than are to be found in any similar work in the whole com- 

 pass of modern science. And yet, when first published, this work 

 seemed so complete and so exhaustive of the subject, that it was 

 some years before any one doubted either the correctness of the 

 observations or the soundness of the conclusions of its author. 

 The name of Ehrenberg was a sufficient guarantee for any state- 

 ment, however marvellous, and his reputed discoveries passed for 

 a time unquestioned. Gradually, however, as the number of 

 observers increased, and as various improvements were made in 

 the construction of the microscope, the views of the great Berlin 

 philosopher were discovered to be in many particulars erroneous, 

 and that one of the two great characters on which he had relied 

 for separating the Infusoria into their main divisions, was alto- 

 gether imaginary. 



According to the classification adopted by Ehrenberg, the Infu- 

 soria formed two principal and well-defined groups. To the first 

 of these he gave the name Polygastrica, from the supposition 

 that all the animalcules composing it possessed several distinct 

 stomachs, united together by a sort of intestinal canal. The 

 second group consisted of the Wheel Animalcules, so named on 

 account of the wheel-like rotation produced by rows of delicate 

 hair-like bodies, resembling eyelashes, and hence termed cilia, 

 which fringe the upper extremity of the bodies of the animal- 

 cules ; and to these Ehrenberg gave the name Hotatoria, or 

 Ilotifera. In these two groups, as the primary divisions, all the 

 Infusoria were included ; and though Ehrenberg was fully sensible 

 of the great dissimilarity between the organization of the Eotifera 

 and that of the various forms included in the other group, he 

 seems to have had no doubt as to the perfect propriety of their 

 being all retained under one and the same general designation. 

 Never, however, have the views of a philosopher, or his supposed 

 discoveries, been more completely set aside by subsequent observa- 



