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IS THE BLEPHAROPLAST A CENTROSOME. 75 
is informed. This is accompanied by a neck extending out from the 
nucleus at the point where the centrosphere is located, the centrosphere 
being extended away from the main body of the nucleus farther into 
the cytoplasm. When this neck or beak has reached its definitive 
length the kinoplasmic rays all bend downward and come to lie in a 
plane parallel to the nuclear wall and fuse together, forming a bell- 
shaped membrane surrounding the nucleus, with the centrosome form- 
ing its apex. By the growth of this membrane the nucleus is finally 
entirely surrounded, together with a portion of the cytoplasm of the 
original ascus, and the ascospore delimited. The same process of 
free cell formation in. the delimiting of spores in the ascus has also 
been carefully described by Harper as occurring in Lachnea and is 
probably a common method of spore formation in asci. The extension 
of the beak from the nucleus which remains in connection with the cen- 
trosphere while the kinoplasmic rays from the latter fuse together and 
form the plasma membrane delimiting the ascospore, is similar to the 
beak from the nucleus of Ginkgo and Cycas which Hirase (62) and 
Ikeno (70) have found to remain in connection with the blepharoplast 
while it is extending in length and forming the cilia of the spermato- 
zoid. This beak connection also recalls the beak of the nucleus which 
extends out to the Mundstelle on the plasma membrane of the cell in 
the formation of the cilia of the swarm spore of Vaucheria as described 
by Strasburger (112, p. 188). That there is an analogous relation 
between the nucleus and the centrosphere, blepharoplast, and J/und- 
stelle, respectively, in the three cases can not be questioned. 
In the Hepatic centrospheres have been described by Farmer (33) 
as occurring during spore formation. They form the center of a series 
of radiations, and do not become visible until the radiations are fairly 
well developed. The center of the system of radiations was not always 
occupied by a single granule or centrosome; often several distinct 
granules were visible, forming a microcentrum in the Heidenhain 
sense. The centrospheres disappear at the close of the division, and 
before each division are apparently originated de novo in the cytoplasm 
of the cell in close relation to the nuclei. The interesting feature in 
connection with the centrosomes here and the blepharoplasts in Zvinza 
is that they are supposed to originate de novo in the cytoplasm of the 
-cell. Studies of spermatogenous cells of the Hepaticee would doubt- 
Jess prove of special interest, as a genuine centrosome being present 
in the divisions during spore formation may also be expected to occur 
in these divisions as well. 
The cases of centrosomes among higher plants, or spermatophytes, 
are all as yet open to some degree of doubt. Various authors have 
claimed to have found special granules at the poles of the spindle, and 
that this is the case can hardly be questioned. In the divisions lead- 
ing to the formation of the pollen in Vymphwa, Nuphar, and L/mo- 
