510 DR. W. R. MCNAB ON WELWITSCHIA. 
parts of the perianth of the female flower. But here the resemblance stops; for while 
the decussating development of parts in the male flower goes on uninterruptedly, in the 
female flower a pause occurs after the formation of the outer part of the perianth, and 
then a ring is formed surrounding the nucleus. Judging from the time of appearance 
and the position of the inner parts of the male flower, there seems every reason to believe 
that they are carpellary. They form in regular order, without break or interruption, 
and decussating with the two primordial stamens. ‘Then they form two semilunar 
cushions like the other parts, which would hardly be the case if they were to be con- 
sidered a single ovular integument. It would thus appear as if in Welwitschia we had 
the first appearance of an ovary, and, if development had not been arrested, the rest of 
the floral axis would have been developed into a terminal ovule. But the arrest of 
growth is so manifest, that sections of the older flowers show the apex to be still very 
small, while the carpels have attained a considerable size. The expanded body must 
therefore be regarded as a stigma with a tubular style, the whole, however, being func- 
tionless, The branching of the stamens also calls for remark. The same process is 
described by Payer in Hypericum, where three or five primordial stamens appear, which 
afterwards branch and produce a number of united stamens. In Welwitschia each 
primordial stamen only produces three, a central and two lateral, which by growth at 
the base form the staminal ring, or monadelphous condition, so well seen in the perfect 
flower. 
Turning to the female flower, we must first observe that the ovule is an axial structure, 
that the end of the axis of the flower forms the ovule. The covering of the nucleus 
may be a single leaf or an axial structure, and would then be, as Professor Oliver has 
described it, an urceolate prolongation of the axis. Other examples of terminal axial 
ovules are known, as in Rheum, Piperaceæ, Naias, Typha and Taxus—which removes 
the chief difficulty in looking at the covering of the ovule as an integument. If it had 
been carpellary, there is every reason to expect that it would have been formed like the 
carpels in the male flower; but such is not the case. - 
Welwitschia would thus seem by the male flower to make a very close approach to 
the Angiosperms, the axis of the flower ending in a mass of tissue, which in the female 
is the terminal ovule; while in the female flower we have the truly gymnospermous con- 
dition, no carpels existing, but a terminal ovule, the modified end of the axis of the 
flower, with a single ovular integument, the pollen grains being applied to the naked 
nucleus directly. 
It is only necessary to allude to Parlatore's description of the flowers of Welwitschia in 
De Candolle's * Prodromus,’ vol. xvi. There seems no reason to consider the parts of the - 
perianth to be bracts. If my conclusions be correct, his description will require to be 
considerably amended. 
