28 Mr. H. J. Carter on the Development of the Root-cell 



appear in its ordinary form or as a whole ; for at present I have 

 a dozen plants with the nucules attached to them respectively, 

 and each plant about one-third of an inch in length, without the 

 least appearance of cortical cells, although each is composed of 

 three or four internodes and several branches ; if the cortical 

 cells appear hereafter, they may, perhaps, be formed like the 

 other cells, viz. by projections of the mother cell- wall, in the 

 form of grooves, which, lodging a portion of protoplasm, are 

 ultimately cut off" from the parent cell or internode ; in which 

 case they must be provided with nuclei from the remnants of the 

 old nucleolus, or nuclei altogether de novo. 



While the component parts of the first cell of the root of 

 Chara are still fresh in the mind of the reader, it seems advisable 

 that they should be compared with those of Arnoeba. Chara 

 lives by nutriment obtained through endosmosis; Amoeba, by 

 taking in the crude material direct, and, having abstracted the 

 nutritious parts by the process of digestion, ultimately throwing 

 off the refuse. Chara is a vegetable, though there are animal 

 cells which also live by endosmose ; but Amoeba cannot be a vege- 

 table, if we admit the distinction that I have given, viz. the 

 taking in of crude material. Nevertheless the root-cell of Chai'a 

 and Amoeba greatly resemble each other. 



Thus the cell-wall of the former corresponds with the pellicular 

 secretion or capsule of Amoeba, which, in Arcella, &c., appears 

 as a shell. The protoplasmic sac may correspond with the pellicula 

 itself and diaphane. The nucleus is identical, and situated in the 

 fixed portion of the protoplasm, as it appears in the fixed mole- 

 cular sarcode of Amoeba, when the latter assumes a spherical 

 form. [In my Notes on the Organization of the Infusoria*, 

 I have called the " nuclear utricle " the " capsule,^^ and the 

 " nucleolus " the " nucleus."] The " granules " of the fixed 

 protoplasm have exactly the same greenish tint and appearance 

 that the " granules " of the sarcode in Amoeba present, and the 

 former appear to be vicarious in function, if not homologous 

 with the green-cell of the plant-stem; that is, when the former 

 make their appearance, the latter disappear. The rotating pro- 

 toplasm corresponds with the internal mucus of Amoeba, to 

 which I would confine the term " sarcode t,^^ and the vacuoles 

 with the vesicula and vacuoles of the substance of Amoeba ; hence 

 it would appear that, as a cavity is formed in the protoplasm of 

 the cell of Chara by the bursting of the vacuoles into each other, 

 round which the rotating protoplasm turns, so it may be the 

 vesicula which thus becomes distended in Amoeba to render it 

 spherical, and hence the appearance of the fixed sarcode on the 



* Ann. and Mag. Nat. Hist. vol. xvii. p. 356. 

 t Idem. See the definition of these terms. 



