Gnetiim , with some Notes on the Structure of Inflorescence . 613 
by comparison appear to be greatly swollen. This disorganization of the 
axial parenchyma is absent from all the material of G. scandens that is 
available for examination. It appears, therefore, that the tendency to 
undergo mucilaginous degeneration is much greater in the African species 
than in others that have been studied. But a somewhat similar dis- 
integration of the tissue of the leaf-base in contact with the axillary bud 
occurs in the seedling of G. Gnemon - 1 
Apart from the remarkable behaviour of the vascular strands supplying 
the flowers in the African species the most peculiar feature of the male 
spike is the basipetal development of the flowers in each ring; this 
character is common to all three 
species, and, so far as is known, no 
species has been described in which 
it does not occur. In G. scandens 
the bundles which supply the flowers 
arise as branches from the leaf-traces 
just before these enter the leaf. 
Such an origin of the vascular 
supply of an axillary bud seems 
to be somewhat rare among the 
cases investigated , 2 but it occurs in 
G. africannm . 3 The stem of this 
species is heterophyllous. So far 
as is shown by the material available, 
branches never arise from the axils 
of the ordinary foliage-leaves, but 
are subtended by reduced leaves 
which bear a close resemblance to 
the sterile leaves on the peduncle ; 
their leaf-traces, from which those 
of their axillary branches arise, are 
as small and frequently almost as 
numerous as those which pass into the cupules of the inflorescence. 
The narrow space between the reduced leaf and its axillary shoot is 
occupied by a dense growth of hairs similar in form and origin to 
those which occur among the flowers of each ring. The flower-ring 
as a whole is, therefore, undoubtedly axillary in position. But the 
basipetal order of development of its members is not paralleled in 
the vegetative organs. A few examples of supra-axillary shoots have 
1 Bower (’82), p. 283; PI. XXV, Fig. 19. 
2 The two bundles from the axillary branch unite at once with two of the leaf-traces in 
Clematis (de Bary (’84), p. 244). 
3 Material of the vegetative parts of G. scandens is not available. 
Text-fig. 6. Longitudinal section through 
