CONTRIBUTIONS TO BOTANY. 
161 
Since the foregoing portion was printed, Dr. Hooker’s memoir 
on Welwitschia has appeared in the Linnean Transactions, which 
renders it incumbent on me to reconsider my former views con- 
cerning Ephedra. That memoir will claim attention from every 
botanist, not only for the careful description of the structure of 
this remarkable plant, but for the admirable manner in which 
the elaborate details of its analyses are illustrated; and it is 
fortunate for science that Dr. Hooker had at his command ample 
materials for the investigation. For the present purpose it will 
be necessary to refer only to such points in that memoir as may 
relate to Ephedra. 
In the absence of the smallest information concerning the 
female dower and the ovary of Ephedra, and with the knowledge 
that in Gnetum the male and female dowers are found in distinct 
whorls on the same node, I had suggested the possibility that 
in Ephedra both sexes might prove to be developed in the same 
common spikelet, in which the male dowers in the lower whorls 
had fallen away before the female dowers became developed in 
the terminal whorl — a supposition rendered more probable by 
the fact that male and fructiferous spikelets are sometimes found 
on the same plant. But the changes shown in the gradual 
development of the ovary and fruit of Welwitschia render the 
above supposition improbable; and by analogy we may now 
form a tolerable conjecture of the nature of the female dower in 
Ephedra. From these data we may infer that the two ovaria 
developed in the terminal pair of involucels are deficient of a 
corolla — a circumstance which sometimes occurs in Euphor- 
biacece, where the male dowers are provided with both calyx and 
corolla, while the ovary is destitute of any doral envelope. 
The application of the term “ cone ” to the dowering heads of 
Welwitschia and Ephedra is calculated to mislead many persons 
in regard to the affinity of the Gnetacece; for they bear little 
analogy to the cones of the Coniferce. They are more properly 
spikelets, because they bear regular petaloid sessile dowers along 
a common axis, much after the manner of a spike of Plantago ; 
and they oder more claims to this category than the spikelets 
of Myrica, the aments of Betula, or the spicated infiorescence of 
many other genera. 
The structure of the male dowers and the mode of indores- 
cence in Welwitschia present a striking resemblance to those in 
Ephedra, both showing an advanced state of doral development. 
Dr. Hooker considers the ovule in the female dower to be deficient 
of any carpellary covering, and therefore gymnospermous ; but 
the circumstances he has demonstrated tend rather to evince 
that it is enveloped in a distinct carpel. The important fact of 
the existence of hermaphrodite or polygamous dowers in this 
Y 2 
