462 BOTANICAL GAZETTE [DECEMBER 
is 120 uw by 80 yw, while the male nucleus is 45 wu by 15 uw. The mem- 
branes of the nuclei are resorbed at the place of contact, and the 
contents of the male nucleus pass into the interior of the female 
nucleus, thereby leaving a protuberance containing very little 
cytoplasm. 
In Abies the chromatin could not be detected definitely until 
the formation of two groups in the micropylar end of the egg 
nucleus takes place. While the groups are still distinct, the indi- 
vidual chromosomes become separate (fig. 28), each group con- 
taining the haploid number of chromosomes. As the two spindles 
unite, the chromosomes become paired (figs. 21-33); at first the 
individuals of a pair approximate side by side (figs. 31, 32); soon 
they twist about one another and jointly loop into the form of a C 
(figs. 30, 32, 33). The chromosomes are very large, in some cases 
exceeding 20 win length. There is abundant evidence that this is 
a pairing, not a longitudinal splitting of chromatin elements. First, 
the number of pairs is haploid. This is the number which would 
necessarily result from a pairing of the double number of chromo- 
somes already present; a splitting would, of course, result in 2% 
airs. Also, the twisting of the chromosomes about one another 
is identical with their behavior in what is generally regarded as a’ 
pairing during the prophase of the first reduction division. More- 
over, there follows a transverse segmentation. If the diploid num- 
ber of chromosomes should undergo two divisions, one longitudinal 
and one transverse, an 8x number of chromosomes would necessarily 
result. The facts cannot be explained by the supposition that 
there is a longitudinal split; they are readily explained by regarding 
this paired appearance as a true pairing. 
The segmentation—The bending into ( or V-shaped forms is 
followed by a segmentation of each component of the pairs; in 
other words, a transverse fission at the angle of the bent chromo- 
somes (figs. 34, 40). The resulting 4% daughter segments are 
approximately 10 w in length, or one-half the length of the pairs 
before and during the looping process. At first the segments 
remain more or less twisted about one another (figs. 34, 37, 41, 42), 
and for some time retain a paired relation (figs. 43, 45). They may 
be in the form of X’s, or V’s, or parallel rods. At the time when 
