of Preissia quadrat a (Scop.), Nees. 417 
epiphylla Farmer and Reeves (1894) describe two minute structures on 
opposite sides of the nucleus in contact with its membrane. Radiations 
extend from these structures into the cytoplasm and later over the nuclear 
membrane; and as the latter disappears, the spindle is formed. At 
opposite poles of the elongated nucleus of cells in the stalk of the archego- 
niaphore of Marchantia polymorpha van Hook (1900) observed a body 
from which radiations extend, some of which penetrate the nuclear membrane. 
Kinoplasmic radiations in the germinating spore of Pellia epiphylla have 
been described by several investigators, first by Farmer and Reeves (1894). 
Farmer (1895) described them as radiating either from a minute centrosome 
or from a group of granules outside of which is a hyaline space. Davis 
(1901) observed asters that radiate from a vague centrosphere-like region at 
opposite sides of the nucleus. Chamberlain (1903) observed caps at the 
poles of the nucleus that become resolved into fibres; and Gregoire and 
Berghs (1904) describe cytoplasmic fibres oriented on the poles of the 
nucleus either on a polar vesicle or on the nuclear membrane, which radiate 
towards the cell membrane or towards the equatorial plane enveloping the 
nucleus. The aster is described as a cytoplasmic network, the rays of 
which are joined among themselves. Both centrospheres and centrosomes 
are said to be absent. In the Mosses Allen (1912) observed plates of 
kinoplasm that occupy opposite sides of the nucleus of the antheridial cells 
of Polytrichum juniperinum . These kinoplasmic plates are formed by the 
division of a single plate into two daughter plates, and are connected by 
fibres. In later divisions the kinoplasmic plates are replaced by bodies, and 
finally by a central body. 
I have studied the process of fertilization in Preissia quadrata at a 
stage when the nucleus of the antherozoid lies near the centre of the egg. 
My material was collected from gorges around Ithaca and prepared for 
sectioning at Cornell University. I am indebted to Prof. G. F. Atkinson 
for the privileges of the botanical laboratory there, where for several years 
I experimented with methods of handling the plants and with various killing 
reagents. The material from which drawings were made for this article was 
killed in the field in a modified Flemming solution. I also acknowledge the 
privileges of the laboratory in the Cornell Medical College at Ithaca. My 
material was stained and studied at the botanical laboratory at Columbia 
University and examined by Prof. R. A. Harper, to whom I am indebted 
for a critical examination of my preparations. 
Fertilization stages in Riella Clausonis have been described by 
Dr. Osvaldo Kruch, who reports that he saw many eggs with one antherozoid 
in the cytoplasm. Both nuclei, before fusion, were approximately of the 
same size. The male nucleus is said to contain eight chromosomes, as 
does also the egg nucleus. Fusion of the pronuclei was not observed, nor 
were astral rays and centrosomes. 
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