EXPLANATION OF THE PLATE. 



Figs 1 — 6, Conferva glomerata, 



F]g 1 The growing pointfe of the plant. — a, Terminal cell , b, Eami- 

 fication of a cell, beguming , c, Ramification further advanced, 

 with the commencement of the formation of a septum at ito 

 base J 4 a perfect septum ; e, Prolongation of a branch- cell 

 twice the length of the cellb in general^ with the commence- 

 ment of the formation of a septum in the middle. 



„ 2. Terminal cell grown to the double length, with an imperfect 

 septum in the middle. 



„ 3. Constriction of the cell-coi\tents by the half-completed sep- 

 tum. 



„ 4. A half-completed septum, in which a considerable deposition of 

 cellulose membrane has already taken place. 



„ 5. A septum in progress of formation after the action of an acid, 

 which has caused contraction both of the primordial utricle 

 (a) and the cell-contents (h) 



„ G Complete septum split into two lamellae by the action of an 

 acid. 



„ 7. The two uppermost cells of a hair from the filament of Trades- 

 cantia Sellowii, with nuclei and currents of protoplasm 



Figs. 8 — II. Formation of the Pollen in Althaea rosea. 



„ 8. Four nuclei in the contents of the parent-cell, with the com- 

 mencement of the formation of four septa. The primordial 

 utricle and cell-contents contracted fiom the action of alcohol. 



„ 9. Farther advanced development of the septa of the parent-cell 



J, 1 0. The primordial utricle removed from the parent-cell, not yet 

 completely divided into four parts 



„ 11 Completed divi^^ion of the parent-ceil 



