158 BOTANICAL GAZETTE [AUGUST 
the time of the third division of the endosperm, it is evident that - 
they are analogous to those of Pinus, as reported by FERGUSON 
(4, 5), although nothing was observed that would correspond to 
those steps in fertilization, as reported by HutcHtnson (12) for 
Abies, which differed from those of Pinus. 
To the writer the finding of the separate, distinct spirems and 
the separate groups of chromosomes is added evidence that the 
chromosomes maintain their individuality from one generation 
to the next. 
In conclusion the writer wishes to state that, according to her 
interpretation of the word “fusion” as used by previous writers, 
there was meant a mingling of the male and female chromatin, so 
that all trace of the individuality of chromatin and chromosomes 
contributed by the respective parents was lost by the time of the 
first division. In this investigation no such fusion was found, 
but instead, an entrance of two or three masses of chromatin, as 
the case might be, into a more or less single nuclear cavity, the 
chromatin contributed by the respective parents remaining dis- 
tinct throughout the preparation for the first division. The 
writer is unable to state whether fusion in the sense of com- 
plete intermingling ever occurs after the completion of the first 
division. 
Summary 
1. After the male nucleus and two polar nuclei come together, 
the separating nuclear membranes persist more or less until seg- 
mentation. 
2. Three distinct spirems are formed in the primary endosperm 
nucleus. 
3. A tripolar spindle, each arm with its group of chromosomes, 
precedes the formation of the bipolar spindle. 
4. The three groups of chromosomes maintain their identity, 
at least until several divisions have occurred. ; 
5. The nuclear membranes separating the egg and sperm nuclei 
disappear earlier than in the preceding case, but the two groups of 
chromatin remain separate. 
