and its Nucleus in Chara verticillata. 23 



appears first, and its nucleoli unite together long before those of 

 the secondary nucleus ; while, although the opposite sometimes 

 takes place, it is rare, for I have only observed it twice. 



As regards the influence of the nucleus upon the development 

 of the new cells, it will now be evident that, if there be any, it 

 must be derived in the first instance from the parent nucleus, 

 for both the extremity of the second root-cell and the projection 

 for the lateral or rootlet-cell take place before the disappearance 

 of the primary nucleus for providing each of these parts with a 

 new nucleus. But as soon as a trace of the septa respectively 

 cutting off these cells from the remaining portion of the fixed 

 protoplasm, and, therefore, from the old or first root-cell, is 

 visible, the new nuclei respectively also appear in their proper 

 situations; after which the further development of the nuclei 

 and septa progresses /?flnjo«s5M. Thus the new cells are never en- 

 tirely without a nucleus, which would thus appear to exert some 

 influence, directly or indirectly, upon their development, for as 

 soon as the only two new cells which the root-cell gives off are 

 formed, the old nucleus becomes effete. At the same time, the 

 general functions of the cell do not depend on the nucleus, for 

 the cell grows larger and the circulation of the rotatory protoplasm 

 continues for an indefinite period after it has ceased to exist ; the 

 latter apparently with even greater activity than when it was in 

 full operation. Whether a new cell-bud can originate a new 

 nucleus for itself, or go on growing to the extent of a nucleated 

 cell without a nucleus, I am ignorant. But I am inclined to 

 the opinion that it can do neither, and, therefore, opposed to 

 the view I formerly expressed, when I knew less about the 

 development of the roots of Chara, viz. that the root-cells of 

 Chara, like the gem mule-buds on the body of Vorticella, might be 

 developed "independently of the cell-nucleus*.'^ I should 

 hesitate, therefore, to assert now, that we might state this with 

 certainty even respecting Vorticella. 



Why the nucleolus should quadruplicate, while the capsule or 

 " nuclear utricle " only (?) duplicates, and, when the division of 

 the latter has been completed, the two nucleoli in each half 

 should unite again into single nucleoli, I am also ignorant. 

 That the nucleus in Chara verticillata does invariably undergo 

 this process in the providing of nuclei for new cells, several 

 single and several repeated serial sets of observations on different 

 root-cells enable me to assert. So evident is this, that on one 

 occasion the nucleoli of the secondary nucleus remained separate 

 for five hours, during which they not only constantly changed 

 their position, but grew larger, so that I thought they would 



i * Ann. and Mag. Nat. Hist. vol. xviii. p. 237, 1856. 



