1900] FERTILIZATION OF ALBUGO CANDIDA 303 
may have important functions to perform during oogenesis. 
The differentiation of the ooplasm and the separation of the 
female nucleus from all the other nuclei of the oogonium which 
pass into the periplasm is a remarkable phenomenon. However, 
there is little or no evidence furnished by morphology as to the 
part which the coenocentrum might play in these activities. On 
the other hand, there is the possibility that the structure may 
represent only an effect of functions concerned with the proto- 
plasm of the oogonium asawhole. It may be the morphological 
expression of dynamic activities deeply seated in the proto- 
plasm, such as might be presumed to operate when the ooplasm 
collects in the center of the oogonium, when the nuclei pass 
outward into the periplasm, and when the female nucleus is 
chosen to preside over the oosphere. This point of view is 
worth considering, although we have not yet enough data to 
safely advance such a theory. 
The nuclei of A. candida are so small that the study of the 
mitotic figure is very difficult. Stages of division are always 
numerous in preparations, because both the antheridium and 
oogonium present a mitosis at one stage of their development, 
apparently affecting all of the nuclei simultaneously. The 
mitosis in the oogonium takes place when the ooplasm is differ- 
entiated from the periplasm; that in the antheridium before 
the penetrating tube has entered the ooplasm. Metaphase is - 
very conspicuous stage. As is shown in fig. ro the spindle is 
entirely intranuclear. The writer was not able to establish with 
certainty the presence of centrosomes, but the nuclear figure 1s 
very small, and proportionally a centrosome might be expected 
to be exceedingly minute. The chromosomes are granular, and 
the number can only be estimated with great difficulty, but 
Wager’s view that there are about 12 or 16 is probably correct. 
They arise from a linin network that may be readily stained in 
the resting nucleus (fig. 9). The nuclear membrane persists 
until late anaphase, as. is illustrated in fig. 77, where the two 
sets of daughter chromosomes are shown separated and massed 
at the poles of the elongated nucleus. The old nuclear membrane 
