It frequently happens in conjunction with this separation of the carpels one from the other, that a lack of union manifests itself between the margins of the individual carpels themselves. Very numerous cases of this kind have been recorded, and the double tulips of gardens may be referred to as showing this condition very frequently. In connection with this detachment of the carpels, a change in the mode of placentation is often to be observed, or two or more kinds may be seen in the same pistil, as in double-flowered saponarias, many Crucifers, &c., as alluded to under the head of displacements of the placenta. FOOTNOTES: [75] _Loc. cit._, p. 298. [76] Masters in Seemann's 'Journal of Botany,' 1867, p. 158. [77] Bull. Soc. Bot. France,' t. xiii, 1866, p. 234. [78] 'Bull. Bot.,' pl. i, figs. 8-12. [79] 'De Anthol.,' p. 37. [80] Moquin, loc. cit., p. 305. [81] 'Neue Denkschr. der Allg. Schweiz. Gesell.,' band v, pl. ii. p. 5. [82] 'Hesperides,' auctore Ferrario. Rome, 1646, fig. 415, pp. 213 and 215. See also Michel, 'Traite du Citronnier.' [83] 'Ann. des Science Nat.,' 3rd series, 1844, vol. i, p. 294. [84] 'Org. Veget.,' vol. ii., p. 41. CHAPTER III. SOLUTION. The isolation or separation of different whorls that are ordinarily adherent together is by no means of rare occurrence. Were it not that the isolation is often congenital, the word detachment would be an expressive one to apply to these cases, but as the change in question occurs quite as often from a want of union, an arrest or stasis of development, as from a _bona fide_ separation, the word solution seems to be, on the whole, the best. It corresponds in application to the word _liber_ (_calyx liber_, &c.), in general use by descriptive botanists. As here employed, the term nearly corresponds with the "adesmie heterologue" of Morren. Moquin Tandon does not make any special subdivision for the class of cases here grouped together, but places them all under "Disjonctions qui isolent les organes." It seems, however, desirable to have a separate word to express the converse condition of adhesion, and for this purpose the term solution, as above stated, is here employed. Diagrammatically, the condition may be expressed by placing a dotted line at the side of the letters thus: : s s s s s : : c c c c c : would indicate the disjunction of the sepals from the carpels (c), in contradistinction to adhesion, which may be represented by the unbroken line thus: | s s s s s | | c c c c c |