VOLUME XXXVIII NUMBER 1 
DHOTANICAL GAZETTE 
JULY, Fo0d 
SPERMATOGENESIS AND OOGENESIS IN EPHEDRA 
TRIFURCA. ng 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY. 
W. J. G. LAND. 
(WITH PLATES I-V) 
THE Gnetales are exceedingly important from a morphological 
standpoint because of many points of contact with angiosperms. 
That they have not received the attention their character warrants 
is probably due to the difficulty encountered in obtaining material 
suitable for critical morphological study. 
Ephedra, comprising about twenty species, is confined to the 
warmer arid regions of the northern hemisphere, and is evidently 
more nearly related to the Coniferales than is either Tumboa or 
Gnetum. s = 
- Important morphological literature dealing with Ephedra is 
extremely scanty. In 1872 Strasburger published an account of 
Ephedra altissima and E. campylopoda, dealing with the develop- 
ment of the microsporangiate and megasporangiate strobili. In 
1879 he described stages in the development of the embryo in &. 
altissima. Jaccard (’94) described in a fragmentary way E. helvetica, 
giving most attention to spermatogenesis. He also gave some atten- 
tion to fertilization and early stages of embryogeny. 
The present study was undertaken with the hope of being able to 
follow in a fairly complete way the life-history of E. trijurca Torr. 
This account, dealing with spermatogenesis and oogenesis, is to be fol- 
lowed shortly by another dealing with fertilization and embryogeny. 
I 
