1896, ] The Life-History of Sequoia. 337 
not always. The cells in the upper end are as a rule larger 
than those in the lower end. 
The date of maturation of the archegonia seems to vary as 
muchas a month. The archegonia are numerous and usually 
arranged radially in the upper half or third of the prothallium, 
sometimes distributed to the upper end and sometimes not. 
They are, then, as a rule lateral. Only a few preparations 
showed the archegonia. In these the archegonia were nearly 
as long as half the transverse diameter of the prothallium and 
each consisted of a small neck cell and a large egg-mother 
cell (fig. 10, s, ¢ ). The farther development of the arche- 
gonia remains to be studied. 
By July 5th the central part of the upper half of the pro- 
thallium contains several intertwined tubular suspensors each 
with an eight- or twelve-celled embryo on the lower end (figs. 
Wand 12). The origin of the proembryos (suspensors with 
Ab ha ys j . ary each grain con- 
he time the pollen is shed in January ell with a large 
tucleus, and a smaller, lenticular, parietal 
Nucleus. The germination of the pollen 
the middle of February, and by the end of the t 
| that month the pollen-tube reaches across the flat top of the 
ium 
‘Porangium and begins to grow down between the sporangiu 
i he 
as integument. The vegetative mee riddle pare the 
ube : the mi 
and is usually to be found between tion in the rate 
of development of the pollen-tubes than of the principal em- 
Hyo-sacs, During March the tube may re 
tds the length of the small sporangium an 
dial cell in the microspore enlarg ; 
bic (fig, 8, x Apr. Sth). The two daughter nuclei, 
