OF THE OVARIUM OF SIPHONODON. 137 
this torus being produced, as in Nymphea, Victoria, &c., into a styliform and stigma-like 
body. Each carpel bears two ovules on each of the ten marginal placentæ, making twenty 
ovules in all. The annulus is the free upper portion of the five confluent carpellary leaves ; 
the five ridges are the lines of junction of these; the five stigmata are each double, 
formed by the terminations of the confluent placental margins of the adjacent carpels, as 
in Papaveraceæ and many other Orders. 
There is one point, however, to which further allusion is necessary, as possibly in part 
explaining Mr. Griffith’s views; and this is, the above-mentioned line of loose cellular 
tissue that extends from the base of the central column to the ovarian cavities, and which 
is met at the ovarian cavity by the true stigmatic tissue. It is very possible that this line 
indicates the existence of a stage in the early state of the ovarium in which the carpellary 
leaves were not completely closed; for though I feel satisfied that the ovules of this plant 
are at no period independent of the carpellary leaves, and are indeed formed in cavities of 
those leaves and from their margins, it does not follow that there may not have been a free 
. opening to these cavities, or one closed only by a very lax tissue. It is indeed held by some 
. botanists, that all carpellary leaves are congenitally open, and close more or less com- 
pletely afterwards; an opinion which is not as yet absolutely proven, though I cannot 
but think that the open ovary of Conifere* and its allies is a strong argument in its 
favour. This however, if true, by no means reconciles Mr. Griffith's observations, or his 
theoretical view of the structure of the ovary of Siphonodon, with my own. 
The structure I have described in Siphonodon suggests a different view of the affinities 
of this obscure genus than those which have been doubtfully adopted by Griffith, though 
in the absence of ripe seeds it will be difficult to establish these, and I shall not therefore 
attempt to do so now. 
In submitting this very singular plant, then, as a strong proof of the validity of those 
laws of carpellary placentation which it has been supposed to have subverted, I cannot 
refrain from expressing my admiration of the learning which Mr. Griffith has displayed 
in his discussion of the view he somewhat hastily adopted ;—of the guarded manner in 
which he expresses his opinion ;—of the full weight he gives to every structural point that 
seems to him to militate against it, and of the candour with which he states every adverse 
argument that suggests itself to him. Though I believe his observations and conclusions 
to be erroneous, it must be recollected that the plant is a very anomalous one, its parts 
exceedingly small, and that my experience assures me that specimens preserved in spirits, 
such as I examined, are in many respects much better for determining structural points 
from than living ones are. Mr. Griffith’s paper further abounds in acute observations on 
many other points in the structure of Siphonodon, to which I have not alluded; and it 
contains, in a note, a short abstract of the only accurate account hitherto published, so 
far as I know, of the development and true nature of the ascidia of Nepenthest. 
* It appears more consonant with the known laws of vegetable morphology to regard the Coniferous ovary as an 
arrest of the usual tendeney of ovaries to close, than to suppose the ovaries of most Phænogams to be congenitally 
closed, and that of Conifers open. 
+ Some years ago I prepared drawings of the development of the pitchers of Nepenthes, from plants in the Royal 
Garden at Kew. These confirm Griffiths observations in every particular, and prove the pitchers to be modifications of 
excurrent midribs. Each pitcher commences as a gland at the anterior apex of the conical mamilla, which represents 
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