Page:Natural History Review (1862).djvu/32

Rh Among these errors may be mentioned the opinion of M. Baillon, laid before the French Academy on the 9th July, 1860. Baillon, after examining the evolution of the flower of Taxus baecata L., Phyllocladus rhomhoidalis, Rich., Torreya nucifera, Lieb., Thuja, Pinus resinosa, Salisburia, Gingko, Sm., and Cupressus, arrived at the opinion that the organs which R. Brown regarded as naked ovules are flowers reduced to a pistil, formed of two carpels, and enclosing one orthotropous ovule reduced to a nucleus; and that these very simple flowers are never inserted on a leaf or "bract" (or rather "carpel"), but always on the axis, on which they are sometimes terminal and sometimes lateral; and further, that the cupule or aril of Taxineæ is a dilatation of the axis, "commonly called a disk."

Now what are the reasons which lead M. Baillon to regard the naked ovule of Robert Brown, and almost all recent botanists, as two united carpels? He states that the first developed part of the flower (or what is usually called naked ovule) of all Conifers consists of two small tubercles, opposite to one another, and shaped like a horse-shoe, exactly resembling the carpels of Amarantaceæ, Chenopodiaceæ, &c., in the first stage of evolution. From this resemblance, he regards these tubercles not as the integuments of an ovule, but as carpels, and states that their apices afterwards form two equal or unequal styles. The nucleus of the ovule, according to him, appears after these carpels. This period of evolution is described in detail in Pinus resinosa, and illustrated by figures. As regards that part of M. Baillon's opinion which relates to the more tardy appearance of that which he calls the ovule, his figures do not show it to be the case; but, on the contrary, in t. 1, f. 10, in which the earliest rudiments of the "carpels" are shown, the ovule is also represented, so that M. Baillon's words are contradicted by that figure. Baillon's statements regarding the evolution of the flower of Conifers are confirmed by M. Payer, who seems to have examined Pinus and Cupressus chiefly. Payer, however, speaks in such a manner of the time of appearance of the "ovule" and "pistil" that it is doubtful which of the two he considers to appear first; but whatever his opinion may be, he, at all events, does not confirm M. Baillon, for he says "the flower appears in Cypresses and Pines as a little protuberance, on each side of which arises a little ridge resembling exactly . . . . . a very young leaf"

The priority of origin of the outer covering (carpels of Baillon), or the central body (ovule of Baillon), should by no means be neglected, as its determination may assist in fixing the nature of both. For if the central protuberance appear first and the external envelope later, the central protuberance is an ovule, because the nucleus appears before the integument; but, on the other hand, if