42 BOTANICAL GAZETTE [JULY — 
three cotyledons are not all equivalent. Here two of the xylem groups ~ 
grow somewhat smaller and approximate and finally join, thus giving 
the diarch root structure typical of the normal seedling. 
7. Abnormalities : 
The tip of the pollen tube of fig. 23 contains a curious body cell — 
which is shown more highly magnified in fig. 23a. Its appearance 
division disintegration of the 
nucleus has begun. 
In fig. 34 a slight irregu 
larity is evident, inasmuch 
as a small fragment of th 
body cell nucleus has been 
FALE Eee to constricted off and left just 
Fic. 2.—Diagrammatic cross-section of the behind in the cytoplasm of 
eas and plumule of Widdringtonia, show- the cell. It is barely pos- 
ing arrangement of the primordial leaves in a : 
dicotyledonous seedling. 
been caused by defective 
preparation, but one other case has been seen in which a small papilla 
protruded in precisely the same direction from the body cell nucleu 
(not figured). Moreover, no such 
phenomenon has ever been seen by 
the writer in the case of any other 
large nuclei, either in Widdring- 
tonia or any other plant. 
One very curious abnormal male 
gametophyte is shown in fig. 44. 
Here the sterile nuclei are in the 
swollen tip of the tube (which is 
surrounded by the usual group of 
archegonia), but the body cell has 
been left far behind. The nuclei are shown in more detail in fi 
44a and 44). It is noticeable that the body cell does not exhibit su 
Fic. 3.—Photograph of a transvers€ 
section of a tricotyledonous seedling- 
