and Fertilization in the Hemlock Spruce . 591 
Further Changes in the Egg and the Ventral 
Canal-cell before the Entrance of the 
Sperm-cells. 
When the nuclear membrane is deposited about the young 
egg-nucleus, the chromatin is in the form of a thick homo¬ 
geneous band which is gradually drawn out until the chromatin 
granules appear distinct on the linin threads. At the same 
time the threads anastomose to form an ordinary cell-reticulum, 
in which several small nucleoli appear (Figs. 29-31). The 
nucleus increases rapidly in size and begins to move down 
toward the centre of the egg. The chromatin now occupies 
chiefly the upper half, the lower part being comparatively 
empty (Fig. 32). As it begins to move, it usually becomes 
elliptical in form (Fig. 33), and remains so until fertilized, 
but if the archegonium is very broad it may remain perfectly 
spherical. As it increases in size, it takes in considerable 
food-material and the network becomes coarser and the 
nucleoli larger. When the centre of the egg is reached, it 
remains stationary in the resting condition until fertilized. 
The granules in the cytoplasm of the egg are arranged in 
rows radiating from the nuclear membrane. This arrange¬ 
ment appears with the formation of the egg and disappears 
with fertilization. 
The nucleoli of the egg-nucleus first appear as minute 
spheres hardly distinguishable from collections of chromatin. 
They increase rapidly in size, however, and apparently unite 
to form larger ones and often a single one of immense size 
(Fig. 35). When first formed, these larger ones are very 
plastic and easily take the sickle-form under the influence of 
fixing agents. Later, the outer shell becomes firm and dense 
and takes a deep purple stain with Gentian-Violet, while the 
vesicular mass within stains feebly with Orange, and shows 
a delicate reticulum probably consisting of dissolved proteid 
substance precipitated by chromic acid. The shell is frequently 
found broken in mounted preparations, and the nucleolus then 
