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1897 ] ZAMIA AND GINKGO 231 
to increase gradually in size. In material collected August 30 
the generative cell was found to have become elliptical in shape, 
its dimensions being now about 45 by 65m (fig. 7). The 
nucleus, on the contrary, had become compressed and was now 
fusiform instead of spherical, its major axis being at right angles 
to the major axis of the cell. It was commonly about 45s in 
length and 18 in width. The centrosome-like bodies had 
increased in size, being now from 2 to 2.5m in diameter. The 
radiating filaments of kinoplasm were still few and short as in the 
preceding stage. Between the centrosome-like body and the 
nuclear membrane on each side of the nucleus a regular spheri- 
cal body of nearly uniform size, 7 to 8u in diameter, had made 
its appearance. It stained bright red with saffranin, the same 
as the nucleolus and centrosome-like body, but not quite so 
intensely. The nature and function of these nucleolus-like bodies 
are still in doubt. That they are not caused by the action of 
fixatives is quite clear, as Hirase® observed them in living 
unstained generative cells. Furthermore, I find them uniformly 
in generative cells at this stage, while in a slightly younger 
Stage they do not occur. Zimmermann” being unable to account 
for these bodies suggested that what Hirase supposed to be the 
nucleus was in reality the generative cell, and that these two 
nucleolus-like bodies were to be considered as vegetative nuclei. 
€ was, however, mistaken in this interpretation, as will be 
apparent from an examination of my figs. 5 and 7. In several 
instances spherical masses of similar material have been observed 
in other locations in the cell. These were smaller and their 
Presence did not apparently affect the size of the main masses 
Situated between the centrosome-like bodies and the nucleus, 
which were also present in the same cell. The reactions of 
these bodies to stains would indicate that they may be masses 
of extra-nuclear nuclein. 
The results of my studies on Zamia and Ginkgo are now 
°On the attraction spheres in the pollen cells of Ginkgo dzloba. Ibid. p. 360; 
also Etudes sur la fécondation et l’embryogénie du Ginkgo biloba. Tid. p. 31 
* Die Morphologie und Physiologie des pflanzlichen Zellkernes 107. 
