330 
NATURE 
[ JANUARY 31, 1907 
mately the same stage of development; it may be, as he 
suggests, that the plant did not fruit, until reaching 
maturity. The seeds of Bennettites are in size like “‘ small 
grains of rye’’; they seem to be exalbuminous, and have 
little in common with the enormous seeds of recent cycads. 
With the exception of a single Italian species, in which 
Solms-Laubach found a few pollen grains associated with 
a female flower, we were in complete ignorance as to the 
nature of the male flowers until the publication of 
Wieland’s results. It was usually assumed that in 
Bennettites, as in true cycads, the flowers were unisexual. 
Whatever interpretations we put on the morphological value 
of the interseminal scales and seed-bearing pedicels, it is 
clear that the female flowers of the fossil genus are 
characterised by a morphological plan far removed from 
Fic. 2.—Restoration of unexpanded bisporangiate strobilus showing enve- 
loping bracts, folded microsporophylls and conical receptacle bearing 
short ovuliferous pedicels, &c. 
that of the leaf-like carpels of Cycas and from the crowded 
carpellary scales of other recent genera. 
Mr. Wieland has conclusively proved that previous views 
as to the unisexual character of the Bennettites flowers 
are incorrect; in most cases, at any rate, the flowers were 
bisexual. He figures several examples of reproductive 
shoots terminating in ovulate flowers like those of Bennet- 
tites Gibsonianus, bearing a basal rim (Fig. 1, s) to which 
was formerly attached a hypogynous whorl of pinnate 
microsporophylls with pinnules reduced to an axis pro- 
ducing numerous synangia and microspores. This assump- 
tion as to the former association of microsporophylls with 
a central group of ovuliferous pedicels is justified by the 
discovery of numerous examples of bisexual flowers, con- 
sisting of an axis terminating in a conical receptacle bear- 
ing the two sets of organs characteristics of what have 
previously been styled female flowers, but differing in the 
smaller size of the seed-stalks and interseminal scales, and 
NO. 1944, VOL. 75] 
presenting the appearance of partially aborted or immature 
female organs. Surrounding this central receptacle there is 
a whorl of several pinnate leaves with their upper portions 
folded inwards between the petioles of the central gyncecium 
(Fig. 2), and bearing rows of synangia of a type but 
little removed from those of modern marattiaceous ferns. 
No specimen has so far been described of a bisexual flower 
in which both andreecium and gynoecium are mature. 
There appear to be two possible explanations: are these 
bisexual flowers comparable with the male flowers of 
Welwitschia (Tumboa), in which the female portion is 
functionless; or have we a case of dichogamy, in which 
the male organs matured first, and were subsequently 
shed? This discovery, first announced in a_ short 
paper by Mr. Wieland in 1899, is of the greatest 
importance as demonstrating the retention in a compara- 
tively little altered form of filicinean synangia and spores 
of the marattiaceous type side by side with female organs 
which foreshadow the angiospermous gyncecium. It is 
impossible in the space at our disposal to attempt to deal 
with the numerous questions of phylogeny—the probable 
line of evolution of the Bennettitales and their relationship 
to modern cycads—but we naturally ask, Is it fitting to 
speak of plants possessing this type of flower as cycads? 
The term cycads used by the author is perhaps justifiable 
if adopted in the widest sense, but the reviewer cannot 
help feeling in sympathy with a view expressed in a letter 
recently received by him from Prof. Nathorst, of Stock- 
holm, that the extension of the designation cycads to 
plants so far removed in the organisation of their essential 
organs from the cycads as we know them __ necessarily 
tends to minimise the importance of fundamental 
differences. 
The generic name Cycadeoidea, proposed by Buckland 
in 1827, is used by the author in preference to Carruthers’s 
genus Bennettites; it would, we think, be better to retain 
the latter name for all cycad-like stems possessing the 
lateral fertile shoots of the type originally described by 
Mr. Carruthers. There is another very different form of 
stem which Nathorst discovered in the Rhztic plant beds 
of Scania bearing fronds long known as a species of 
Anomozamites, and flowers which probably agreed closely 
with those of Bennettites. This stem, which Nathorst 
names Williamsonia angustifolia, is important as demon- 
strating the wide range of vegetative variation within the 
great group Cycadophyta. The discoveries of Mr. Wieland, 
Prof. Nathorst and others demonstrate the impossibility 
of forming any adequate conception of the nature of the 
Cycadophyta—to use Nathorst’s convenient term—if we 
confine our attention to the meagre remnant of that 
phylum which has survived the revolutions in the plant 
kingdom since the beginning of the Cretaceous era. 
In the concluding chapters Mr. Wieland deals with 
questions of phylogeny; while recognising much that is 
suggestive in the treatment of this difficult subiect, we 
feel that there is a certain vagueness in his conclusions 
which, though partly due to lack of data, is perhaps to 
some extent the result of a want of clearness and concise- 
ness of treatment. The initial difficulties have, however, 
been surmounted, and Mr. Wieland has completed with 
conspicuous success a very important section of the work; 
we close the volume with a desire for more, and heartily 
wish the author further success in a field where the oppor- 
tunities are unrivalled. ACTGarsn 
THE RECENT HIGH BAROMETER. 
REGION of exceptionally high barometer readings 
over western Europe was a feature of especial interest 
during a great part of January, the mercury in many 
places attaining to a greater height than any previous 
record, while elsewhere the readings have- scarcely been 
exceeded. To trace the history of this anticyclonic region 
and. to attempt any explanation requires a series of 
synchronous and synoptic charts embracing a large part 
of the northern: hemisphere; possibly this may be under- 
taken by one of our European weather offices when all the 
facts have been collated. It would seem that vessels 
traversing the Atlantic have in many cases experienced 
