Transactions of the Society. 



EXPLANATION TO THE PLATE. 



All figures, unless otherwise stated, drawn with the camera lucida from 

 transverse hand sections of the organs in question. Zeiss 2-mm. oil-immersion 

 lens and CO. 6 used throughout. Magnification 1070, reduced in reproduction to 

 about 460. 



Figs. 1-11. — Eremurus himalaicus Baker. 



Figs. 1-9 illustrate phragmosphere formation in the ground tissue cells of a 

 young inflorescence axis at the stage reached towards the end of 

 April or beginning of May. 

 Fig. 1. — Binucleate cell in which one nucleus is about to divide again (to 

 economize space outline of cell incompletely shown). 

 „ 2. — Chromosomes on equatorial plate. 

 ,, 3.— Spindle with chromosomes at the poles, from a cell which also contained 



a resting nucleus. 

 „ 4. — Initiation of cell plate. 

 Figs. 5, 6. — Early stages in phragmosphere formation. 



Fig. 7. — A phragmosphere with paired nuclei, in a cell also containing a'resting 

 nucleus. 

 „ 8. — Phragmosphere expanding towards the wall of the cell ; chromosome 



of daughter nuclei becoming vacuolate. 

 „ 9. — Phragmosphere coinciding with the cytoplasm lining the cell wall. 

 „ 10. — Nuclei from uninucleate cells just below flowering region in an in- 

 florescence somewhat older than that from which the majority 

 of figs. 1-9 were drawn (gathered May 7, 1915). 

 11. — A normal nucleus (n) and a degenerating nucleus (d) belonging to the 

 same cell (April 27, 1915). The nuclei were not in contact, but lay 

 in difierent focal planes. 



Figa. 12 A-C.—Morus nigra L. May 8, 1916. 



Fig. 12 A.— Spindle in the corner of a large pith cell. (To economize space the 

 outline of the cell is only shown in part.) 

 „ 12 B. — Pith cell, with a phragmosphere enclosing two daughter nuclei. 

 ,, 12 C. — Phragmosphere at a late stage, in a pith cell. 



Fig. 13 (see also figs. 27, 28)— Asparagus officinalis L. May 6, 1915. 



Lobed nuclei, from five uninucleate cells of ground tissue between 

 2-5 and 4-5 cm. below base of head. 



Figs. 14, 15. — Chrysanthemum Parthenium Bernh. Pith cells 

 from an axis gathered June 12, 1915, 



Fig. 14. — Two adjacent cells, one containing a resting nucleus and a second 

 nucleus dividing at the spindle stage (also a cluster of crystals). 

 The second cell contains a phragmosphere, of which only one of 

 the two nuclei is included in the section. 

 „ 15. — Another cell, showing a phragmosphere at a later stage, at which it 

 almost coincides with the primordial utricle. 



Fig. 16. — Selaginella Wildenovii Baker. 



Cell of cortex, with a resting nucleus and paired nuclei in a phrag- 

 mosphere. 



