TgI5] YASUI—DIOSPYROS KAKI 369 
27 inno. 1 (pl. fig. 11). In D. virginiana Miss HAGUE counted 30 or 
more. 
» The longitudinal division of the chromosomes in preparation 
for the homotypic division occurs in metaphase, and at telophase 
the chromosomes become arranged in the spireme and spread over 
the outer cavity of the daughter nucleus. The number of chro- 
matin granules is not the same as the x number of chromosomes; 
and there appear two or three nucleoli in the daughter nucleus 
(pl. fig. 12, a, 6). The homotypic division of the microspore 
mother cell occurs in the usual way. The two axes of the spindle 
fibers of this division are not in any definite relation to one another 
(pl. figs. 13, 14). In wall formation the microspores are in tetra- 
hedral arrangement (pl. figs. 15, 16), and the mother cell wall, 
which becomes mucilaginous and separates the four young micro- 
spores (pl. fig. 17), disappears gradually with the formation of the 
thick wall of the pollen grain. 
At the same time the uninucleate tapetal cells enlarge and 
become multinucleate. These divisions of the tapetal nuclei are 
mitotic at first, but later they become amitotic, after which they 
begin to disorganize when the homotypic division of the mother 
cell has been completed (pl. figs. 20, 21, 22). 
The mature pollen grain is spherical, with remarkable canals 
upon the surface of the wall (pl. fig. 18). The cytoplasm occurs 
as a thin layer surrounding a large central vacuole. In general 
only a single nucleus was observed in the pollen grain, pl. fig. 19 
representing the only specimen in which two nuclei were observed. 
The foregoing account of microspore formation was obtained 
from material of no. 1. I have investigated no. 3 also, but could 
not determine the number of chromosomes. The pollen grain is a 
little larger than in the case of no.1. The anther of no. 3 contained 
many withered pollen grains. 
Development of pistillate flower 
The pistillate inflorescence usually appears upon an upper 
branch, consisting of one flower and two bracts that suggest the 
position of flowers that have disappeared. The bracts usually 
