866 Dr. G. C. Wallich on an undescribed Indigenous AmcehB.. 



digenous Ehizopods, which can hardly fail to excite interest. 

 I beg to state, however, that the present and former communi- 

 cation on this subject must only be regarded as of a preliminary 

 nature, and published with a view to afford naturalists an oppor- 

 tunity of personally investigating the organisms in question. 

 When it is borne in mind that we are now treating of creatures 

 holding the lowest position in the scale of being, and that it has 

 been customary to assign to them a degree of simplicity of struc- 

 ture wholly incompatible, so far as all analogy teaches, with the 

 vital functions they are known to perform, it will, I think, be 

 allowed that this unlooked-for phase in the history of the Rhi- 

 zopods cannot be too minutely scrutinized. 



From a further supply of the material containing the Amoeba 

 obtained towards the close of March, it would appear that the 

 form is tolerably plentiful — occurring, however, only in those 

 shallow pools, highly impregnated with ferruginous matter, that 

 are to be met with in certain parts of Hampstead Heath. In 

 the clear pools not a single specimen, having the novel characters 

 I have described, is to be found. 



Out of the numerous individuals examined by me, I should say 

 that not more than 5 per cent, have been deficient in the villous 

 patch ; and from the mode in which some of the larger specimens 

 have been rent asunder by pressure whilst under observation, 

 so as to form two distinct beings, there seems every reason to 

 believe that these apparently exceptional specimens have been 

 produced by similar means. Under the circumstances, I think 

 the Amoeba may safely be regarded as a well-marked species, and 

 I accordingly propose that it should be named A. villosa. 



I mentioned in my former notice that the contractile vesicle 

 and nucleus were generally to be seen in the vicinity of the vil- 

 lous patch, and that, in a single example, the latter had assumed 

 the shape of a spherical tuft attached to the body by a cylindrical 

 pedicle of sarcode. During the past month I have bad ample 

 opportunity of verifying the observation that, in the majority of 

 specimens, so long as the villous patch is not being employed as 

 an organ of prehension, but is merely dragged along in rear of 

 . the main body, the nucleus and contractile vesicle retain their 

 position in its vicinity, but that they circulate with the other 

 contained matters whenever the prehensile action of the villi is 

 not in abeyance. Several specimens have exhibited the tuft and 

 pedicle, but not in so symmetrical a form as the first one ob- 

 served by me. These are very material points, inasmuch as they 

 tend to prove that some kind of consentaneous action takes place 

 between the contractile vesicle, the nucleus, and the villous area, 

 even independently of the appearances now about to be described. 



In several specimens, a delicate funnel-shaped tubule was 



