Proceedings of the Linnean Society of London - University Library

52 PEOCEEDIIS'GS OF THE
of the fact, long overlooked, that Griffith had already described
and figured this organ, more than 20 years before. Eenault
had an important share in the preparation of the splendid
volume on Silieified Seeds, published posthumously in Brongniart's
name.
It was only for a short time that Eenault delivered regular
courses of lectures on Fossil Botany, but his teaching work bore
permanent fruit in the publication of his famous ' Cours de
Botanique Fossile,' in four volumes, 1881-85, by far the most
important general work on the subject up to that time, and still
an invaluable storehouse of facts, based almost wholly on original
observation.
A somewhat earlier and more special work, tlie ' Structure
comparee de quelques Tiges de la Flore Carbonifere," 1879, had
prepared the way ; for in this memoir, among many other researches
of importance, he published his complete account of all the organs
of the extinct Gymnospermous family Cordaiteae— perhaps the
greatest contribution which he, or any botanist before him, had
made to our knowledge of the plants of the past. It may be
mentioned that Eenault, in observing the structure of the pollengrains
within the pollen-chamber of Cordaiteau and other fossil
seeds, was led to anticipate the discovery o£ Ikeno and Hirase,
suggesting the probability that in plants of this group fertilization
took place by means of sperraatozoids.
Eenault's work on the higher plants of the Palaeozoic Period
was crowned by the completion, in 1896, of the magnificent
' Flore Fossile d'Autun et d'Epinac,' of which the first volume is
the work of Zeiller, and the second tliat of Eenault. This was in
many respects his finest work, and the series of more than
60 plates, by which the volume is illustrated, is a worthy monument
of the mass of detailed research which the text contains.
Eenault was much engaged in controversy, more especially with
our own distinguished countryman, Williamson. They differed
principally on the question of the affinities of the Sigillariese and
Calamodendreje ; families which Williamson regarded as essentially
Cryptogamic, belonging to the Lycopodinean and Equisetineau
series respectively, while Eenault, following Brongniart, was led
to place them among Gymnospermous Phanerogams, relying, to a
great extent on the fact that these plants developed secondary
wood, like Phanerogamic trees. The result has justified the
opinion of Williamson rather than that of his great French rival
but it has been well pointed out, that even if wrong in detail,
Eenault and the French school represented by him deserve great
credit for having realized that among related plants, some might
be on one side, some on the other, of the ideal Phanerogamic-
Cryptogamic boundary. Eecent work on other groups has abuudantly
justified Eenault's point of view.
During the last ten years of his life Eenault allowed himself to
be to a great extent diverted from the important stiidits on which
;