and its Nucleus in Chara verticillata. 31 



Vacuoles now appear iu the fixed protoplasm surrounding the 

 primary nucleus prepTiratory to its being broken down into the 

 rotatory form (fig. 3 i) . 



4:th stage.— Kere the fixed protoplasm surrounding the pri- 

 mary nucleus becomes entirely broken down by the vacuoles^ 

 and the whole of it, blending with the adjoining rotatory por- 

 tion, now flows freely with the latter, over the septum both of 

 the second root and lateral or rootlet-cells (fig. 4 A). While this 

 has been taking place, the primary nucleus has moved a little 

 backwards, and has become permanently fixed to the proto- 

 plasmic sac, where the cell-wall has also become elliptically di- 

 lated, apparently to receive it {d, d'). Vacuoles make their ap- 

 pearance in the midst of the protoplasm of the second root-cell 

 near its septum (fig. 5 m) ; while this cell, now elongated, also 

 gets a twist to one side, from the increased development of the 

 rootlet-cell. 



The nucleus in the lateral cell now disappears and returns in 

 the way before mentioned, viz. in two parts, each containing two 

 nucleoli. These undergo the same changes as those before de- 

 scribed,ending iu a conjunction of the nucleoli of each nucleus (o,o). 

 Meanwhile a longitudinal septum has become developed in the 

 lateral cell {n), which is thus divided into two, respectively pro- 

 vided with nuclei. 



The second root-cell has become more elongated, and the 

 vacuoles have worked a cavity in it, round which the protoplasm 

 is slowly rotating (fig. 6/). 



The lateral cell has become divided again by a transverse sep- 

 tum {s), which has been accompanied by a division of the nucleus 

 and quadrisection of the nucleolus as before stated ; so that there 

 are now four divisions in the lateral cell, each of which presents 

 a single nucleus with a single nucleolus, respectively formed in 

 the way mentioned {q, q, q, q). 



5th stage. — The second root-cell has reached the state of the 

 first previous to the appearance of the secondary nucleus (tig. 6 a) ; 

 each of the four lateral cells has become elongated, but in dif- 

 ferent degrees, as in the case of the roots developed from the 

 root-cell of the embryo-sac ; one or two in the latter are gene- 

 rally much longer than the others. Meanwhile the primary 

 nucleus has become enlarged, has presented the vacuoles in its 

 mucus-contents to which I have alluded, and its nucleolus has 

 become divided up into a number of small opake nucleoli (fig. 5 d). 

 These disappear and leave the old nucleus in the form of a flat, 

 elliptical, structureless, effete piece of cellulose (?) (fig. 6 d) ; or 

 the nucleus becomes prolonged backwards in the form of a long 

 cell, and the small nucleoli drawn out with it into diff"erent 

 shapes and lengths (fig. 13 a, a, o). What becomes of the small 



