ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
57 
BOTANY. 
A. GENERAL, including the Anatomy and Physiology 
of the Phanerogamia. 
a. Anatomy. 
(1) Cell-structure and Protoplasm. 
Structured the Cell-wall.* — Dr. L. Buscalioni has studied the 
structure and mode of growth of the cell-wall, especially in the endo- 
sperm and suspensor of Phaseolus multijlorus , and in the seeds of 
Corydalis cava. 
Before fertilization, the wall of the embryo-sac of Phaseolus displays 
at certain spots, slight thickenings and fringe-like projections into 
the sac, and the young cells of the suspensor have similar internal 
projections ; at these spots the protoplasm becomes denser, and ex- 
hibits, after a time, the reactions of lignin. While this change in the 
protoplasm is proceeding, the cell-wall becomes gradually thicker, and 
both it and fine granulations which appear on its surface are stained 
blue by chlor-zinc-iodide, and the sharp distinction between the cell- 
membrane and the protoplasm disappears ; the microsomes formed at the 
spots where the new cell-walls are to appear are gradually converted 
into cellulose. Bows of cellulose-granules now make their way further 
into the cell-cavity, and gradually assume the form of branching anasto- 
mosing rodlets, which are still to be made out in the fully formed cell- 
wall. Besides these rodlets, crescent-shaped lumps and free granules of 
cellulose are formed. 
The increase in thickness and surface of the cell-wall is brought 
about neither by intussusception nor by apposition, but by transforma- 
tion from protoplasm in contact with the membrane ; it can take place 
only when there is contact with already formed cellulose. The micro- 
somes are transformed directly into grains of cellulose ; the hyaloplasm 
into the uniting substance which causes the striation and lamination. 
It is not uncommon for portions of protoplasm to become enclosed within 
the masses of cellulose. 
The structure of the ovule of Corydalis cava is described in detail at 
the time when it is ready for impregnation. Its coat at this period 
consists of an epiderm, a layer of cubical cells, and a layer of cells 
elongated tangentially, and there is also a large aril. In the process of 
cell-division in these layers, the phenomena correspond in all essential 
points to those witnessed in the embryo-sac of Phaseolus. The micro- 
somes of protoplasm, which are arranged in rows along the inner surface 
of the cell-walls, are gradually transformed into cellulose-grains, begin- 
ning from the centre ; and these grains are converted, in their turn, into 
rodlets, or into new layers of cell-wall superposed on those already in 
existence. The author believes that the purpose of these rodlets is to 
give strength to the cells in which they are formed. 
Malpighia, vi. (1892) pp. 3-40, 217-28 (3 pis.). 
