14 BOTANICAL GAZETTE [JULY 
The ventral nucleus remains in the upper part of the archegonium, 
and enlarging (fig. 42) becomes very conspicuous. The egg nucleus 
passes to the center of the archegonium, enlarges, and surrounds 
itself with a mass of cytoplasm, slightly different from that farther 
away from the nucleus in that it at first consists of radial strands 
proceeding out from the nucleus in all directions. A thickening of 
the cytoplasm next appears all around the nucleus at the place where 
the radiations meet the general cytoplasm of the archegonium. This 
thickening is very pronounced in most instances, again it can be 
seen with difficulty; it very much resembles the first appearance of the 
membrane around the egg and synergids of angiosperms. 
SUMMARY. 
Ephedra trijurca is monosporangiate, but bisporangiate strobili 
occasionally occur. 
The beginnings of the staminate flower were clearly apparent in 
December, and the pollen was shed about the middle of April, the 
interval being thus a little over four months. 
The anthers develop in acropetal succession on a strobilus, and 
are surrounded by a perianth. 
Microspore mother-cells were observed about the middle of Feb- 
ruary, and the reduction division occurs about one month later. 
The gametophyte number of chromosomes is twelve. 
There are two persistent prothallial cells; the first is cut off by a 
wall; the second is not cut off by a wall. 
The primary spermatogenous cell surrounds itself by a membrane 
(Hautschicht?), and on the division of the primary spermatoge- — 
nous cell, the stalk cell and body cell continue to be surrounded by 
this membrane, and are not separated from each other by a wall. 
The only wall formed in the pollen grain is the one which cuts off 
the first prothallial cell. 
The male gametophyte at the time of shedding consists of two 
prothallial cells, stalk cell, body cell, and tube nucleus. 
The megasporangium is surrounded by two integuments, the 
outer of which consists of four fused leaves; the inner of two fused 
leaves. 
The megaspore mother-cell is deeply placed within the nucellus 
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