CYCADEM. 
the lamina terminates above, points to a dichotomous branching of the leaf, the rachis 
of which may therefore be considered as a sympodium composed of the basal 
portions of the successive bifurcations, while the lateral leaflets represent the bifur- 
cations of the lamina of the leaf, the growth of which is arrested and flattened. 
The whole leaf would therefore be a dichotomous cymose branch-system. Re- 
searches into the history of its development are however wanting, as in the case of 
the branching of the stem and root. 
The Flowers of the Cycadese are always dioecious, and the plants are therefore 
either male or female. Both kinds of flowers appear at the summit of the stem, 
either singly, as in Cycas, as terminal flowers of the primary stem, or in pairs or 
larger numbers as in Zami'a muricaia and Macrozamia spiralis^ where they may 
perhaps be regarded as metamorphosed bifurcations of the stem\ The flower con- 
sists of a strong conical elongated axis, sometimes supported on a naked peduncle, 
but densely covered in other parts by a large number of staminal and carpellary 
leaves arranged spirally. 
In Cycas the female flower is a rosette of foliage-leaves which have under- 
gone but slight metamorphosis (Fig. 343), the apex of the stem developing again 
first of all scale-leaves, and then new whorls of foliage-leaves ; the stem, therefore, 
grows through the female flower, thus furnishing an instance of prolification. The 
separate carpels are, indeed, much smaller than the ordinary foliage-leaves, but are 
essentially of the same structure; the lower pinnae are replaced by ovules, which 
attain, even before fertilisation, the magnitude of a moderate-sized ripe plum, the 
fertiUsed seed acquiring the dimensions and the appearance of a moderate-sized 
ripe apple, and hanging quite naked on the carpel. Whether the male flower of 
Cycas also exhibits prolification I do not know, and it seems improbable ; the very 
numerous staminal leaves are much smaller, 7 to 8 cm. long, and undivided; they 
expand considerably from a narrow base and terminate in an apiculus. They are 
furnished on the under side with a number of densely-crowded pollen-sacs ; the 
whole flower is from 30 to 40 cm. long. 
The male and female flowers of the remaining genera of Cycadese resemble 
fir-cones externally. The comparatively slender floral axis rises as a rachis on a 
short naked peduncle, and on this are seated the numerous staminal or carpellary 
leaves (Fig. 344). The axis terminates with a naked apex which undergoes no 
further development (Fig. 344 U). The stamens are, indeed, but small in comparison 
to the foliage-leaves of the same plant, but are, nevertheless, the largest which 
occur anywhere among Phanerogams. In Macrozamia, as in Cycas, they are from 
6 to 8 cm. long, and as much as 3 cm. broad ; they spring, with rather a narrow 
base, from the floral axis, and expand into a kind of lamina, terminating in an 
apiculus {Macrozamia^ or in two curved points {Ceratoza?Tiia), or the lower part of 
the stamen is thinner and stalk-like and bears a peltate expansion {Zamici). They 
are also distinguished from the stamens of most other flowering plants by their 
' The hypothesis that the male flower of Cycas Rumphii is one, the leaf-bud by which the stem 
is prolonged the other bifurcation of the dichotomising apex of the stem, is not supported by 
De Bary's recent researches. [According to Warming {loc. cit.) all the flowers are probably terminal ; 
possibly the male flower (in Ceratozamia longifolid) is produced on a branch of a dichotomy of the 
stem : it is certainly not borne on a lateral branch.] 
