NAMED RAFFLESIA. 379
The stnictiirc now dcsci-ibcd actually exists in many im families of plants ; and the priiK'i[)al deviations from it
ovaria agree, consists in their essential parts, namely, the pollen and ovula, being produced on the margins of the modified leaf.
In the yintheric, which arc seldom compound, and whose thecre are usually distinct, the marginal production of pollen is generally obvious.
In the Ovaria, however, where, with very few exceptions, the same arrange- ment of ovula really exists, it is never apparent, but is always more or less concealed either by the approximation and union of the opposite margins of the simple pistillum, and of the compound when multilocular ; or in the unilocular pistillum with several parietal plaeenire by the union of the corre- sponding margins of its component parts.
The i<:^\K cases of apparent exception, where the ovula are inserted over tlic whole or greater part of the internal surface of the ovarium, occur either in tlic compound pistillum, as in Isijmphcpa and Nuphar; or in the simple pistilhim, as in Butomcre of llichard ; and in Lardlzabale<s, an order of j)lants suflrieientiy distinct in this remarkable character alone, and differing also in the structure of endjryo and in habit, from Meuifpermea?, to wliieh the genera composing it {Lurdlzahala and Stauntonia) have hitherto been referred.
The marginal production of ovula, though always concealed in the ordinary or complete state of the Ovarium, not unfrerpicntly becomes apparent where its formation is in some degree imperfect, and is most evident in those devia- tions from regular structure, where stamina are changed, more or less com- pletely, into pistilla. Thus, in the case of the nearly distinct or simple pis- tillum, it is shown by this kind of montrosity in Sempervhum iedorum; in the compound multilocular pistillum, by that of Tropaolam majus; and in the com- pound pistillum with parietal placenta;, by similar changes in Cheiranihus Cheiri^ Cochlearia armomcia, Papaver nudicaule, and SalLv oleifoUa.
In all the cases now quoted, and in several others with which I am ac- quainted, it is ascertained that a single si amen is converted into a simple pistillum, or into one of the constituent ])arts of the compound organ: a fact which, in my opinion, establishes the proposed type of Ovarium.
I have entered thus slightly at present into the proof of this type, derived from these deviations from regular structure, partly on account of an observa- tion which I find in the second edition of the excellent Tlirorie Elcmeiifaire dc la Bolaiiique of Professor De Candolle, to whom, in 1S16, I had shown drawings of most of the instances of monstrosity now mentioned. To these drawings, and to my deductions from them with regard to the structure of pistillum, I suppose the ingenious author alludes, in the passajje in question. His views, however, on this subject differ considerably from mine, which he does not seem to have been aware were already published {J^lnn. Soc. Trans. I.e.)
]\[y second observation relates to the more imporlant differences between the anthera3 and ovaria, independent of their essential parts.
In the Antliera the vascularity, with relation to that of the Leaf, may be said to be diminished without being otherwise sensibly modified; the pollen is formed in a cellular substance apparently destitute of vessels; and is always produced internally, or under the proper membrane of the secreting organ.
In the Ovarium, on the other hand, the vascularity, compared with that of the Leaf, is in general rather modified than diminished ; the principal vessels occupying the margins or lines of production, and giving off branches iowards the axis, whose vascidarity is frequently reduced. The ovula constantly arise from vascular cords, and, with reference to the supposed original state of the ovarium, are uniformly produced externally; though by the union of its parts.
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