HOOKER OK WELWITSCHIA. 
207 
to the bracts of other flowering plants. The organ contained in the 
axil of each of these bracts is quite unlike anything else in the Vege¬ 
table Kingdom, and from a consideration of its matured condition 
only it might be regarded as (1) a modified branch, as (2) the modified 
leaf or leaves of an axillary arrested bud, or (3) as an open carpel or 
pair of carpels. Its development from its first appearance as a minute 
compressed mammilla, has been traced, and so also has been the de¬ 
velopment of the ovules and their integuments upon its inner surface. 
Developmental history has not as yet thrown any certain light upon 
the homology of this axillary scale. Two distinguished German 
botanists, Profs. Braun and Caspary, however, think they find this 
light in a monstrous condition to which the cones of some of the Pine 
tribe (especially the Larch) are subject. In these monstrous cones 
the hardened ovule-bearing scale is metamorphosed into an axillary 
shoot through a series of gradations showing, according to Caspary, 
that the scale is made up of the first pair of leaves of this unde¬ 
veloped shoot, the leaves becoming connate, laterally dilated and 
woody. According to this teratological evidence, therefore, the 
ovuliferous scale is foliar. In so far it may be the homologue 
of the carpels of Angiosperms. It appears to us, however, that 
this evidence is by no means satisfactory. Admitting that the scale 
is a modified condition of the rudiments of an axillary bud, we see no 
sufficient reason why the lower portion of the scale, which bears the 
ovules may not be axial rather than foliar, since Caspary himself 
admits that the hooked appendix arising from the upper surface and 
near the middle of the scale indicates the apex of an evanescent 
axis.* Por notwithstanding many arguments to the contrary, urged 
especially with much force and skill by Caspary,f we fail to see 
why, at least in some cases, the ovule may not be an axial rather than 
a foliar production. In Gnetum and Welwitschia , there appears to 
us no room for doubt on this head. Dr. Hooker observes in respect 
to it (in Welwitschia ) “ it is organically absolutely terminal, being 
erect, central, and continuous with the axis of the perianth without 
constriction, both in the male and female flowers."We are not 
without a rather strong opinion that the embryo-sac and its contained 
embryo and endosperm actually becomes deeply invaginated in the 
extremity of the axis in Welwitschia and Gnetum , and probably many 
other genera of Gymnosperms ; as the vascular cords traversing the 
sides of the seed-coat up to the level of the calyptiform cap (in the two 
genera named) would indicate. In the ‘ hermaphrodite 5 Welwitschia , 
where the ovule is not impregnated., the calyptriform integument never 
* Vide N. H. R. ii. 25. (Dr. Thomson’s translation.) 
f Dr. Caspary seems carried a little too far in his indignant polemic against the 
French organogenists. The view which he upholds regarding the foliar relations of 
the ovule-coats of Primulacese, seems to us untenable, and we think essentially the 
same homology might have been argued for on more plausible grounds. 
t Page 30. 
