45 8 Ferguson . — The Development of the Egg and 
nucleus are repeated, except that a nucleolus does not gene- 
rally become apparent within these nuclei. When they have 
attained full size they pass to the base of the oosphere. 
During their descent many fibres arise in the cytoplasm 
surrounding the nuclei. Some of these threads run parallel 
with the walls of the nuclei, while others extend out from 
the nuclei in a radial manner. These fibres become more 
prominent as the nuclei approach the base of the oosphere, 
and, as in the case of the egg-nucleus, they are most strongly 
developed along the upper sides of the nuclei (Figs. 77 , 77 $, 
78 , and 78 b). When these nuclei have nearly reached the 
bottom of the egg, the nutritive spheres have almost dis- 
appeared from the cytoplasm, those which still persist being 
much reduced in contents (Fig. 78 ). After the four nuclei 
have arranged themselves at the ‘ organic apex ’ of the 
oosphere, in a plane perpendicular to the major axis of the 
archegonium, a marked change occurs in the cytoplasm of 
their immediate vicinity. It becomes dense, coarse, more or 
less granular, and has a great affinity for stains (Figs. 79 
and 79 b). Blackman describes the formation of cell-walls 
between these nuclei, but, in the five species of pines which 
I have studied, cell-walls do not arise until after eight nuclei 
have been formed. 
The early prophases, as also the meta- and ana-phases 
in the mitosis of the four segmentation-nuclei, correspond 
in every respect with the same stages in the second division 
following fertilization ; and it is probable that the chromo- 
somes are derived from two distinct spirems as in the first 
and second divisions occurring within the egg ; but, as already 
indicated, the steps in the origin and development of the 
chromosomes have not been carefully traced in this division. 
These nuclei divide simultaneously. Chamberlain states that 
‘ in the division of the four nuclei the spindle is extremely 
broad and multipolar.’ 1 have occasionally observed such 
a figure during this mitosis, but here, again, great variation 
exists. Every transitional form may be presented during 
metakinesis between a multipolar diarch spindle, which fills 
