174 BOTANICAL GAZETTE [SEPTEMBER 
improbable. The impossibility of the central body either being 
or containing a nucleus has been sufficiently discussed on 2 
previous page. The search for the single nuclei proved in vail. 
The refuge left for an adherent to the idea of a simple fertili 
zation, involving only two sexual nuclei, lies in the assumption 
that the nuclei of the compound oosphere ( figs. 68, 69) have 
descended from a fusion nucleus, which, owing to its rapidity of 
development may have escaped observation in earlier conditions. — 
That is to say, fertilization might have occurred at a stage simi- 
lar to that presented in fig. 6g or earlier. If this were true we 
would expect to find the ooplasm presenting 2, 4, 8, 16, 32, 4 
etc., nuclei, in stages following the division of such a fusioa 
nucleus. As a matter of fact no such conditions were ever 
observed, or is there the slightest evidence that they could be 
present. The oosphere when first differentiated contains 40-32 
nuclei, derived from the mitotic figures that line up in the mat 
ner shown in figs. 64,65. This number is increased to about 100 
by the mitoses in the compound oosphere (jig. 70), and thet 
comes the observed act of fertilization (fig. 85), the discharge a 
from the antheridial tube of a large number of sperm nuclei and 
the subsequent fusion of these in pairs (fig. 88) with the female i 
nuclei. Previous to the act of fertilization the antheridial 7 1 
gradually fills with nuclei as it presses deeper into the ooplas®: | 
There is of course a time when the tube contains a single nuclets a 
but this is when it is about one third the size finally reached, am a 
long before it shows any indication of opening. : os 
It is true that ly i enesis the dense cy top 
very early in oog — 
the interior of the oogonium may contain a small and very" 
able number of nuclei, as is shown in figs. 62, 62s 64. Oe : 
can be no doubt that these conditions represent part of ger a 
ess of zonation, and they have been discussed in that sect an 
this paper headed “Differentiation of the compound oosph a 
It is very probable that stages similar to these might ein the 
where there is only one nucleus left behind in the oospher ge 
process of zonation, but the condition of the antheridial 
ae oe 
all the further history of the oosphere show that this is »° i 
