PAPERS ON BOTANY 139 
cell of the plant body. When near maturity each antheridium 
consists of a more or less globular mass of cubical cells, sur- 
rounded by a wall layer and united with the main body of the 
plant by a relatively short thick stalk. In the majority of the 
liverworts, at least, if not also in the mosses, the protoplast of 
each cubical cell gives rise by oblique division to two cells which 
when viewed from one side present a triangular outline. The 
two triangular protoplasts, Allen of Wisconsin has termed an- 
drocytes. Each androcyte becomes transformed into a sperm. 
Hence two sperms are eventually developed from each of the 
cubical cells. The occurrence of the last division in an oblique 
plane seems at least not so constant and prominent in the 
mosses as in the liverworts. 
The protoplast, or organized protoplasm of one of these 
cubical cells, consists of a nucleus and cytoplasm. The outer 
boundary of the cytoplasm next to the cell wall forms a very 
delicate membrane, the plasma membrane. The remainder of 
the cytoplasm is more or less finely granular or lumpy when 
fixed and stained. Allen, however, finds in one of the mosses, 
Polytrichum, a certain part of the cytoplasm, the kinoplasm, 
organized into definite granular plates or membranes. The 
individual granules of the plates he calls kinetosomes. These 
kinoplasmic plates are present in the resting stage of the cell 
and seem to actively function in spindle formation as the cell 
prepares to divide. 
The nucleus of this cubical cell, or androcyte mother cell, 
is spherical and sharply delimited by a distinct membrane, the 
nuclear membrane. The most prominent content of the nu- 
cleus is chromatin material variously arranged. Either a 
very distinct densely staining nucleolus may be present with 
surrounding chromatin granules in a more or less clearly de- 
fined, often sparse net work, or the chromatic material may be 
almost entirely included in one densely staining central nu- 
cleolar like mass. It seems quite evident that during a certain 
prophase of division whether a distinct nucleolus may be ob- 
served or not, the chromatin becomes largely collected into a 
mass in the center of the nuclear cavity. This mass, some- 
times presenting an irregular, sometimes a smooth outline, 
is resolved into a more or less closely wound or irregularly 
gathered spireme. From this spireme the chromosomes are 
