Review. 
231 
affords an interesting confirmation of Dr. Kidston’s conclusions. 
The question of the specific identification of Dr. Kidston’s specimens 
with Sphenopteris Honinghausi is discussed. Chodat has attributed 
sporangia of quite a different type to Lyginopteris ; the reviewer 
may point out that the pinnules on which such annulate sporangia 
as those figured by Chodat are borne ( Pteridotheca spp.) are 
certainly not identical with the leaflets of Lyginopteris. 
The evidence for the attribution of the seed Lagenostoma 
Lontaxii to Lyginopteris is judicially summed up, and the conclusion 
accepted. The possibility of insect agency in the transport of 
pollen is recognised. 
The account of the genus Heterangium is well up to date. 
Dr. Margaret Benson’s observations are regarded as almost 
amounting to a demonstration of continuity between vegetative 
organs and seeds ( Sphcerostonia ).' 
The family Medulloseae (Chap. XXX) is based on anatomical 
characters, while the alternative name Neuropterideae is restricted 
to fronds. Attention is called to the great length of the Medullosean 
stems, specimens of M. stellata, for example, reaching a length of 
nearly 8 metres, and of 3^ metres without a leaf or branch. It is 
suggested that these long stems with scattered leaves may have had 
a climbing habit, and a comparison is made with the anatomy of 
certain tropical lianes. An excellent comparative account of the 
structure of the stem is given, with a useful set of diagrams (p. 92) 
and there is a striking quotation from White about the “ amazing 
engineering experiments ” which Nature was trying in this group in 
Palaeozoic times. 
The author considers that there is little or no doubt that the 
fronds of Medullosa anglica bore seeds of the genus Trigonocarpus. 
The seeds discovered by Dr. Kidston in connection with leaflets of 
Neuropteris heterophylla and obliqua (by Kidston and Jongmans) are 
regarded as showing a close affinity to Trigonocarpus. 
The subject of the male organs, about which our information 
is still scanty, is fully considered. Potoniea and Codonotheca are 
cited as probable microsporangiate fructifications of this group, 
while the problematic Whittleseya, formerly referred to the 
Ginkgoales, is compared with Doleropliyllum, both being probably 
microspore-bearing leaflets of Pteridosperms, possibly Medulloseae. 
Colpoxylon , with from 1 to 7 steles, is maintained as a distinct 
genus. The new figures of this stem are welcome. The imper¬ 
fectly known fossil Rhexoxylou africanum is described, in accordance 
with Miss Bancroft’s results, as a polystelic stem related to the 
Medulloseae. 
In connection with Sutcliffia, Dr. Ethel de Fraine’s suggestion 
of the two courses of evolution which may have started from this 
type—a monostelic line leading to the Cycadophyta, with a poly¬ 
stelic branch to the more complex Medulloseae—is discussed. The 
author evidently inclines to this view, while giving full weight to the 
arguments of Worsdell and Matte in support of a polystelic ancestry 
of the Cycads. The reviewer is quite in sympathy with Miss de 
Fraine’s hypothesis, but feels that connecting links between Sutcliflia 
and the Cycad type are badly wanted. 
5 On p. 81, Sphenopteris obtusifolin is a misprint for S. obtusiloba. 
