TO SPERMATOGENESIS AND FECUNDATION OF ZAMIA. 
forming organ enters the egg and remains in the cytoplasm in Zama 
and Cycas is certain and not open to any question. 
The writer has endeavored by diligent search to observe the forma- 
tion of the first segmentation spindle, but thus far has been unable to 
succeed. However, he has been able to observe the spindle in the 
second division which leads to the formation of four daughter nuclei. 
Here the spindle is of normal form, but rather drawn out at the poles. 
No differentiated body can be observed at the poles of the spindle which 
could be considered a centrosome. In the later divisions also very many 
dividing nuclei in various stages have been carefully studied, but with- 
out success. In no case of dividing nuclei in the early cleavage divi- 
sions before the seed matures has any centrosome been observed. This 
statement corresponds entirely with the writer’s earlier conclusions 
reached in 1897 (124). In the case of Ginkgo and Cycas also, accord- 
ing to the researches of Hirase and Ikeno, no centrosomes or centro- 
spheres could be found in the early divisions of the egg nucleus. 
Aside from this very conclusive evidence that the blepharoplast 
brought in by the spermatozoid does not form a centrosome which 
takes part in the formation of the first segmentation spindle, the con- 
clusion is indubitably established furthermore by the fact that the 
ciliferous band remains intact at the apex of the egg cell for some time 
following the division of the egg nucleus. It has been observed 
unbroken after at least five or six divisions when the daughter nuclei 
had become spread here and there in the ege cell. In several 
instances nuclei resulting from the division of the egg nucleus have 
been found occupying a position between the spirals of the ciliferous 
band. This was very puzzling when first discovered before the 
development was understood. 
The division of the eg@ nucleus results in a decided reduction in the 
size of the nuclei until they are reduced from the tremendous size of 
the egg nucleus, which is visible to the unaided eye, to rather small 
nuclei not above an ordinary size. The first two or three divisions 
take place while the nuclei remain grouped together in the center of 
the egg cell in the position of the original egg nucleus; after this the 
nuclei become gradually scattered throughout the egg cell and finally, 
in the first stage of the organization of the embryo, form a layer of 
ceJls around the periphery of the egg cell. The history of the forma- 
tion and development of the embryo, however, has no place in the 
present memoir. The writer will discuss this matter at some future 
time in another place. 
IS THE BLEPHAROPLAST A CENTROSOME? 
The feature of most interest in this investigation is the question 
regarding the true nature of the blepharoplasts or cilia-forming organs 
of the spermatids. When these organs were first observed in Ginkgo 
by Hirase in 1894 (57) he referred to them as attractive spheres, as 
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