10 SPERMATOGENESIS AND FECUNDATION OF ZAMIA. 
Ginkgo, being distinct from typical centrosomes in their main fune- 
tion, namely, that of forming the motile cilia of the spermatozoid, 
were here named blepharoplasts. 
Early in 1898 Ikeno, ina short paper in Flora (69), announced the 
occurrence in the spermatids of Cycas revoluta of cilia-forming organs 
like the blepharoplasts of Zamza, and claimed that these and the 
Nebenkern of the Filicineee and Equisetinez are nothing but genuine 
centrosomes. . 
Later in 1898 Shaw (102) described the occurrence of blepharoplasts 
in the spermatid mother cells of Onoclea and Marsilia which developed 
into a cilia-bearing band, as in the cases described by Belajeff. Shaw, 
however, was able to demonstrate the occurrence of similar bodies in 
the primordial mother cells (Urmutterzellen). At the close of the 
division which gives rise to the primordial mother cells small round 
bodies, called by Shaw dlepharoplastoids, became visible. During the 
resting stage of the nuclei the blepharoplastoids divide into two, 
increase In size, and remain near the,nucleus. As soon as the nuclei 
of these cells prepare to divide the pair of blepharoplastoids move 
away from the necleus and take a position at one side in the cytoplasm 
about midway between the pole and the equator of the spindle until 
near the end of the metakinesis stage, when they disappear. The ble- 
pharoplasts proper appear as very small bodies, one at each pole of the 
spindle, about the time that the blepharoplastoids disappear, or occa- 
sionally shghtly before. During the resting stage of the spermatid 
mother cells the blepharoplast divides into two, and these gradually 
separate and move to a position in the cytoplasm near where the poles 
of the next spindle is formed, but always slightly to one side of this. 
After the completion of the division they become extended into the 
cilia-bearing band. 
In June, 1898, Hirase’s complete monograph on the fecundation and 
embryology of Ginkgo appeared (62), describing in detail the develop- 
ment of the spermatozoids. The cilia of the spermatozoids are here 
developed from a membrane, which is formed from the blepharoplast, 
the same as in Zama, differing only in minor details. The writer con- 
siders the blepharoplast to be nothing more than a centrosome and 
ealls it such throughout his monograph. Hirase described the sper- 
matozoids of Ginkgo as having a well-developed tail attached to the 
posterior end, which would make them seemingly quite different from 
the spermatozoids described by the writer. Many features of this 
monograph will be discussed in the present paper in comparison with 
Lamia. 
In the report of the Boston meeting of the American Association 
for the Advancement of Science, published in Science November 11, 
1898, the writer (127) described the phenomena connected with the 
bursting of the blepharoplast in Zamna at the close of the division giv- 
ing rise to the spermatids and the formation of the cilia-bearing band. 
