7 
Embryo of Cephalotaxus drupacea. 
are at first perfectly spherical and of equal size. As shown in Figs. 7 and 
8 they eventually lie close together and soon lose their spherical form. 
They become slightly elongated and seem to cling or fold about each other, 
as shown in Fig. 8. This condition was very frequently observed just 
prior to their entrance into the archegonium. When the sperm-nuclei are 
completely organized the chromatin is in the form of uniformly small 
granules with two or three deeply-staining nucleoli. 
Surrounding the nuclei there is very little starch present, which is in 
contrast to the conditions generally found at this stage in the Cupressineae, 
and to which Coker (’ 03 ) seems to attach some importance. 
As we shall point out later, both sperm-nuclei, still folding over one 
another, may enter a single archegonium together, or they may separate 
a short distance apart just before entering. It invariably happens, however, 
that they both enter the same archegonium. 
The history of the male gametophyte in Cephalotaxus drupacea covers 
a period of about fifteen months. In none of its phases does it show any 
noticeably primitive characters as compared with other Coniferales. 
The Female Gametophyte. 
There were two difficulties in the way which prevented the securing of 
a satisfactory series of preparations to show the development of the 
megaspores. First, because the three trees, from which all the material 
was obtained, did not produce flowers in abundance, I hesitated to sacrifice 
the later history of the gametophyte for the sake of the early megaspore 
stages ; and second, because the hard thick tissue enveloping the young 
ovule prevented the rapid penetration of the killing fluid, it was almost 
impossible to obtain a satisfactory fixation of the cells concerned, the 
ovules themselves being too small to remove without injury. In one 
preparation I was able to make out a single large megaspore mother-cell 
and in another a large megaspore with two smaller cells, one above the other, 
which I interpret as disorganizing megaspores. As to the reduction division 
and the events immediately following I was unable to trace further. 
It seems almost certain, however, that only one megaspore germinates, 
and that its early germination proceeds very slowly. As the megaspore 
enlarges, the usual free nuclear division takes place. In several cases six 
or eight free nuclei were found in the cytoplasm. A central vacuole very 
soon makes its appearance, which increases in size and gradually forces the 
cytoplasm and free nuclei to the periphery. Fig. 9 shows a longitudinal 
section through the young female prothallium, with the very large central 
vacuole and the parietal layer of cytoplasm, in which the free nuclei are 
distributed at more or less regular intervals. Up to this time the parietal 
layer of cytoplasm is but a very delicate film. As shown in Fig. 12 it is 
not even as wide as the diameter of the nucleus. The character of the 
