960 TJioday and Berridge . — The Anatomy and Morphology of 
adjoining its flattened side (Text-fig. II. 11) and run unbranched into the 
apex. In E.fr a gdis the median bundle does commonly contribute a small 
bundle to the outer integument. 
In E. alata and E. Torreyana there are three large bundles in the 
outer integument, derived exactly alike from the three bundles entering the 
base of the ovule. The integument in these species has three large project- 
ing wings, one in the median and two in the lateral planes. 
The five or seven bundles left in the flower axis form a ring which 
dies out low down in the base of the ovule and does not as in Welwitschia 
and Gnetum run up into the base of the inner integument. From the position 
of the ring the constituent bundles here also are clearly integumental. 1 
The simple nature of the vascular system 
of the ovule in Ephedra as compared with that 
of the other Gnetales is very striking, and, 
like the unbranched pair of bundles supplying 
the leaves and bracts, would appear to point 
to reduction in this genus. 
(ii) E. altissima. The main differences 
between this species and E. distachya in the 
course of the bundles in the axis of the 
strobilus and flowers depend on the fact that 
in E. altissima there is usually only one 
ovule. There is, however, a considerable 
range of variation in this species, and it be- 
comes clear from an examination of the 
different cases that the uniovulate is a modi- 
fication from the biovulate condition. 
Case 1. Biovulate cones with both ovules 
fertile are occasionally found. In these cases 
the course of the vascular bundles is prac- 
tically identical with that described in the 
cone of E. distachya , except that in the cases examined the integument 
always received three vascular bundles, and not two as is the rule in 
E. distachya , the median axillary bundle branching into three and con- 
tributing as well as the other two 2 to the integument. 
Case 2. Among the material in the laboratory in Manchester, cases 
frequently occurred in which the single nut of the uniovulate cone had four 
angles instead of the normal three, and four bundles supplied the outer 
integument 3 (Text-fig. V), running up these four angles. The course of the 
1 See pp. 966, 967. The tissues of nucellus and integument in Ephedra are differentiated from 
one another down to the base of the ovule. 
2 In E. trifurca , in which species also there is commonly only one ovule in the strobilus, 
biovulate cones also occasionally occur, in which the course of the bundles is the same as in Case i 
of E. aliissima. 3 This is the normal case in E. trifurca (see also Land, 1904). 
Text-fig. v. Transverse section 
through base of ovule described as 
Case 2. The section is taken just at 
the level at which the outer integu- 
ment with its four bundles is in the 
act of becoming free, b = upper 
cupule; r= Ting of vascular tissue 
entering base of inner integument ; 
c = suberized layer at the base of 
nucellus. 
