38 Mr. H. J. Carter on Amoeba princeps 



to prove that the sarcode moves round by itself, unless we 

 assume that its analogue the protoplasm of the plant-cell (ex. gr. 

 in Nitella) possesses this property ; and, bearing on this point, 

 M. Garreau observes : — "In proportion as the merithalli [inter- 

 nodal cells] are developed, this matter [the rotating protoplasm] 

 gets fixed to the primordial membrane, in the formation of 

 which, indeed, it takes part, and which, though adherent to the 

 cell-wall, propels onward the enclosed liquid of the cell, not, as 

 has been suspected, by the aid of vibratile cilia, but by tolerably 

 rapid undulations, similar to those produced on the surface of 

 water ruffled by a gentle breeze"*. The primordial membrane 

 supports the chlorophyll-cells in the internode, and retains them 

 in their fixed position ; but when the contents of the internode 

 collapse under injury or death, this membi'ane leaves the internal 

 surface of the cell-wall, here as well as in the root-cell, where 

 there are no chlorophyll-cells — showing that it is still organized, 

 and analogously placed to the diaphane in Amoeba. I confess 

 that M. Garreau's meaning is a little obscure here, i. e. as to 

 whether by the " liquid of the cell " is meant the " axial fluid " 

 or a remaining rotatory portion of the protoplasm. But his 

 allusion to an undulatory power of a fixed membrane of the cell 

 is distinct. How far his interpretation in this respect pertains 

 to fact remains for future observation to determine. 



Such, in conclusion, however, are our difficulties in the right 

 appreciation of physical signs when we come down to this region 

 of organized life, that, unless we can state in a few words 

 the facts which we may wish to establish, it is useless to have 

 recourse to long argumentative theories for this purpose. 



In ^thalium, although of far greater tenuity than in Amoeba, 

 and therefore more nearly allied to the protoplasm of the plant- 

 cell, there is still a homogeneous superficial layer corresponding 

 to the diaphane. 



Vesicula or Contracting Vesicle (PI. III. fig. 1 b). — The normal 

 number in A. princeps is one; but there are many smaller 

 ones which act as sinwses around it, and one of these occasionally 

 becomes so enlarged as to look like a second vesicula, yet it 

 also ultimately discharges its contents into the main one. Where 

 the vesicula discharges itself, it again recommences to appear ; 

 and there, also, the accessory sinuses may be best seen as they 

 successively become dilated and discharge their contents into 

 the vesicula. 



It is a remarkable fact, that although the vesicula is borne 

 round the interior of A. princeps with the sarcode to which it 



* Ann. Nat. Hist. vol. x. p. 116; translated from 'Ann. des Sc. Nat.' 

 torn. xiii. 1860, p. 189. 



