285 
bable that formerly more than a single whorl of bracts 
were fertile, having found a cone of E. altissima with 
small masses of abortive tissue in the axils of the bracts 
next below the fertile ones, suggestive of undeveloped 
sporangiophores. 
Occasionally a female flower is found in a staminate 
strobilus. 
The ovule is composed of two coverings, an outer and 
an inner one, and a nucellus. 
The outer integument, or perianth as it is called by 
some authors, is entirely free from 
the central part and is connate with 
the inner one at its base only. It 
contains two, three or four ribs and 
according to Coulter and Cham- 
berlain (51) ,appears first in two 
distinct parts” (p. 378), It is built 
up of two layers, an inner fibrous 
one, comparable with a sclerotesta 
and an outer layer, composed of 
great brown cells covered by an 
epidermis which may be homologous 
with a sarcotesta. 
The inner integument is never 
more than two cells thick, which 
are thin walled and parenchymatous, 
and in its upper part is prolonged 
Fig. 10. Éphedra ame- jn a very long micropylar tube, 
ricana; longitudinal section : : 
reaching far beyond the strobilus. 
through the ovule; outer 
integument, inner integu- AÀt its inner side the micropyle is 
ment with a long micro- eularised 
pylar tube closed by a Cuticularised. 
prop of mucilage, nucellus The nucellus, concrescent for two 
ss ee thirds of its height with the inner 
integument is sharply demarcated 
with its large empty cells from the smaller ones of the 
