116 Dr. G. C. Wallich on the Value of 



tions of these forms, and there were no grounds for assuming 

 that one of these varieties approached more nearly to it than 

 the rest, I had no alternative but to designate my new form 

 by a new specific name — leaving it to be determined hereafter 

 whether Amoeba princeps and those other forms which have 

 received distinct specific appellations, on trivial differences in 

 their. configuration, are or are not mere transitional phases of 

 the most highly developed type, namely, A. villosa *. 



Fortunately the means of verifying or refuting every state- 

 ment advanced by me with regard to A. villusa, both in matters 

 of fact and deduction, are at hand, and will become more and 

 more abundant as soon as favourable habitats for this Rhizopod 

 shall be discovered. But should any lingering doubt remain as 

 to the impropriety of altering the original definition of A. prin- 

 ceps, in order to render it conformable with the characters ob- 

 servable in A. villosa, it is only necessary to refer to Mr. Carter's 

 declaration t that " Ehrenberg^s J and Dujardin's§ figures are 

 good representations of^' A. princeps, and to beg the reader to 

 examine the plates and definitions here alluded to. On doing 

 so, he will find that neither in the figures themselves nor in the 

 letter-press definition accompanying them is reference made to 

 a single character on which I have based the typical stability of 

 A. villosa 11 . 



* The following extract from Mr. Carter's supplementary paper on " the 

 Infusoria of Bombay," published in 1857, will show that, whilst he is fully 

 alive to the necessity of re-naming an imperfectly defined form, he has put 

 the principle into practice on diiFerences of structure which bear no com- 

 parison, in point of importance, with those now assigned to Amoeba villosa : 

 — " Euglypha pleurostoma is very like Ehrenberg's Difflugia Enchelys and 

 Dujardin's Trinema acinus ; but not being identical with the figure given 

 of the former, and though often presenting three radiated prolongations 

 like the latter, but by no means so constantly, it becomes necessary to give 

 it a name." (Ann. Nat. Hist. ser. 2. vol. xx. p. 35.) 



t Ann. Nat. Hist. July 1863, p. 31. 



X Infusionsthierchen, Atlas, fol., tab. 8. fig. 10 (1838). 



§ Hist. Nat. des Zoophytes, Atlas, plate 1. fig. 11. 



II I subjoin the definitions in question : — " A. princeps. J. major dilute 

 flavicans, sextam lineae partem repens, processibus variabilibus, numerosis, 

 eylindricis, crassis, et apice rotundatis." (Ehrenberg's Infusionsthierchen, 

 p. 126.) 



" A. princeps, majeure. Large de 037 a 0'60, blanc jaunatre. Remplie 

 de granules qui refractent la lumiere, et se portent ou refluent dans les 

 expansions successivement formees, lesquelles sont tres-diaphanes a I'ex- 

 tremite et souvent tres-longues " (Dujardin, Hist. Nat. des Zoophytes, 

 1841, Paris); whilst appended to the plate is the subjoined remark, dis- 

 tinctly indicating that, irrespectively of the granules, there was nothing to 

 show the direction in which the animal might be moving:— "EUe est 

 avancee a la fois ses deux branches en y poussent la substance glutineuse 

 dont elle est formee avec les granules nombreux et varies qui s'y trouvent 

 engages et qui montrent bien la direction du mouveraent " {loc. cit.). 



