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64 ON THE SEXUAL OKGANS OF THE CYCADACE^.
a tliorough revision, be found untenable, the characters relied on being
either inconstant, or at most of merely sectional value, and the so-called
genera being linked with each other by all kinds of gradations. Par-
latore, who is by no means indisposed to recognize genera based on
comparatively slight characters, provided these are constant, writing of
those employed for the dismemberment of Scirpus, well observes,—
" Geneve immeritamente diviso in molti, fondati sopra caratteri falsi
della presenza o mancanza delle sete del perigonio, dello stilo bifido o
trifido, deir achenio triangolare o schiacciato, caratteri tutti variabili
in questa faraiglia, non solo nelle specie di uno stesso genere, ma an-
cora negl' individui di una stessa specie, e fino nelle spighette di uno
stesso individuo."
ON THE SEXUAL ORGANS OF THE CYCADACE^.
By r. A. W. MiQUEL.
{Translated hy W. Thiselton-Dyer, Xj^., B.A.,/rom the author's French edi-
tion of the paper puhlished in the 'Archives Neerlandaises,^ t. iii. 1868.)
In 1845, when I published some researches on the ovules, em-
bryos, and male organs of the Cycadacffje (Ann. des Sciences Nat.
3me serie, t, iii. et iv.), Gottsche published in the ' Botanische
Zeitung' an important investigation of the same subject. The results
of these wholly independent researches were, in many points, identical
but Gottsche had taken a more comprehensive point of view by in-
cluding the Coniferce as well. At that time I had already completely
abandoned the morphological views which I liad previously published
(' Monographia Cycadearum ') on the axial nature of leaves, as well as
llichard's theory of the ovule. Eobert Brown, by his investigations of
the genus Plnus (" On the Plurality and Development of the Embryos
in the Seed of the Coniferce," Annals of Nat. Hist., May, 1844), had
ensured still more suppo;i't for his theory of gyranospermous ovules
first stated in 1826 (Appendix to Captain King's ' Voyage ').*
It is well known how much the labours of Mirbel, Spach, Schleiden,
* Previously read at the British Association Meeting at Edinburgh. Robert
Brown afterwards added a note, to the etrect tliat the credit of the first idea of
tiiis theory does not belong to Mirbel; and he states that Aiibert du Petit-
Thouar.s had already noticed various points in the structure of the ovules of
Cycas, without deducing from them the notion of gymnospermous ovules.
(Histoire des Vcget. des lies d'Afrique.)
; •