164 ARCHEGONIATES. 
The development of the archegonium is the same as in the lower 
gymnosperms. The ventral canal-cell is separated from the egg merely 
by a plasma membrane, which is formed by the connecting fibers, as 
is usual in the higher plants. It persists for a short time only. In 
Age 
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St.c.” 
Fic. 68.—Pollen grain, end of pollen tube, and fusion nucleus of Pinus strobus.—(After Ferguson.) 
A, mature pollen grain. 4! and 42, remains of first and second prothallial cells; a. c., antheridial cell. 
B, pollen grain in which antheridial cell has divided. g.c., generative cell; s¢.c., stalk cell. 
C, distal end of pollen tube which is pushing between neck-cells of archegonium; the male nuclei (s.#.) 
are of unequal size. wv.#., tube nucleus; sé.c., stalk cell; s.c., cytoplasm of generative cell. 
D, first mitosis following fecundation. The spindle is formed, but the male and female chromatin 
spirems are still separate and distinct. 
Pinus strobus, according to Ferguson, there are probably instances 
in which the nucleus of this cell is not reconstructed, and this may be 
true also in other genera and species. 
