Beer . — On the Development of the Spores of Ricci a glanc a . 279 
the daughter-nuclei is shown in Fig. 11. On first reaching the apex of the 
spindle the chromosomes are crowded closely together (Fig. 12). Soon, 
however, a nuclear membrane is formed and the chromosomes proceed to 
open out. 
During the earlier stages of the telophase a number of chromatic bodies 
can be seen distributed upon the linin, and these bodies are no doubt the 
derivatives of the chromosomes (Figs. 13 and 14). At a later stage the 
scattered chromatin bodies have come together to form a single lobular 
nucleolus, whilst linin fibres, containing little or no stainable material, 
extend through the nuclear cavity (Figs. 15 and 16). The spindle during the 
metaphase and anaphase of the division is a comparatively narrow structure. 
A conspicuous cell-plate is developed at the equator of the spindle (Fig. 12). 
During the telophase of division the spindle shortens and broadens out 
very considerably and the cell-plate becomes correspondingly broader 
(Fig. 14). 
A membrane is developed at the equator of the spindle, no doubt 
between the split halves of the cell-plate, although the splitting of the plate 
could not be followed here on account of its great delicacy. This mem- 
brane, which stains rather deeply with bismarck-brown, does not at first 
reach right across the cell (Fig. 15), but by the time that the nuclei are again 
dividing it has almost or quite reached the periphery of the cell (Fig. 17). 
After a short interval of rest the nuclei enter upon the second maiotic division. 
At the conclusion of this division cell-membranes are formed which 
complete the division of the mother-cell into the four daughter-cells, which 
are conveniently, if incorrectly 1 , called the special-mother-cells. These 
membranes, separating the special-mother-cells from one another, give both 
cellulose and pectose reactions, as do the secondary and tertiary thickening 
layers of the mother-cell which still form the peripheral envelope of the 
tetrad group. 
It may be mentioned here that during the development of these septa 
a large proportion of the starch of the cell is seen to be aggregated in their 
neighbourhood (Figs. 17 and 18). 
The special-mother-cell walls do not long remain in this condition, but 
secondary thickening layers are soon deposited upon the inner surfaces of 
the thin pectose-cellulose membranes (Fig. 19). 
These thickening layers have an uneven outline, forming the papillate 
projections into the interior of the cell, which previous writers have fully 
described. Their reactions show that they consist of callose apparently 
unaccompanied by any other substance. They colour deeply in coral 1 in - 
soda, in aniline-blue, in congo- red and in naphthol-black 2 . On the other 
1 Miss Benson, New Phytologist, vol. iv, 1905, p. 96. 
3 I have elsewhere dealt with the specific staining properties of naphthol-black (see Beihefte zum 
Bot. Centralblatt, Bd. XIX, Abt. I, Heft 2, 1905, p. 289). 
U 
