Professor Seward's 11 Fossil Plants." 23 ^ 
The structure of the flowers ( Cordaianthus ), so familiar from 
Renault’s drawings, is now illustrated by photographs of Prof. 
Bertrand’s, which are interesting if not always clear. 
In the next chapter (XXXIV) the family Pityese is described. 
A note by Dr. Gordon, referring to his unpublished observations on 
Pitys, will be read with much interest. He finds medullary as well 
as circum-medullary xylem-strands in P. primceva and ailtiqua, and 
also in his new species, P. Dayi. A closer connection with the 
Kentucky genus Archceopitys is thus established. In P. Dayi the 
leaves and leaf-traces have been investigated. The leaves are quite 
different from those of Cordaites and their structure “ tends to 
accentuate the possible relationship of Pitys with the Lyginodend- 
reae ” (p. 288). 
While Zalessky’s Devonian genus Callixylon undoubtedly finds 
its right place in the Pityeae, the inclusion of other genera, such as 
Parapitys , Ccenoxylou, and Mesopitys 1 is more open to discussion. 
Antarcticoxylon, possibly allied to Mesopitys , is of interest from the 
high Southern latitude (74°, S) at which it was found. 
Chap. XXXV is concerned with such Palaeozoic Gymnosperm- 
ous seeds (the great majority) as cannot be definitely assigned to 
their parent plants. The main divisions Radiospermese and 
Platyspermese are not adopted, and the seeds are grouped in three 
classes, Lagenostomales, Trigonocarpales and Cardiocarpales, the 
two former being essentially radiospermic, and the last platyspermic. 
The subject of Palaeozoic seeds is as difficult as it is important, and 
students will find the author’s full synopsis of the greatest service. 
In Chap. XXXVI we come to the great class Cycadophyta, the 
dominant Seed Plants of the Mesozoic. The chief division is of 
course that of the Bennettitales, including Williamsonia ; Chap. 
XXXVI deals with the Benettitales proper, and the following 
chapter with the “ Williamsonian tribe,” to use Wieland’s phrase. 
The author, “with some reluctance” gives up the use of Carruthers’s 
name Bennettites for the genus, and adopts Buckland’s Cycadeoidea, 
which has the priority and has been constantly employed by the 
American investigators in their classical work. Dr. Marie Stopes’s 
attempt to discriminate between Buckland’s Cycadeoidea and 
Bennettites by structural characters is criticised, and her conclusions 
regarded as insufficiently established. 
The complex organisation of Cycadeoidea is fully described. 
The author suggests a doubt whether the megasporophylls in some 
of Wieland’s bisexual flowers, were “ merely immature or function¬ 
less as in the male flower of Welwitschia” (p. 379). The former had 
generally been assumed, but the question raised calls attention to 
the need for a fuller investigation of the ovular stage of the gynEeceum. 
There are some further data in Wieland’s second volume, which 
came too late for the author to make use of it. 
The significance of this wonderful group of plants is well 
expressed in a quotation from Lester Ward: “ Cycads are to the 
vegetable kingdom what Dinosaurs are to the animal, each 
representing the culmination in Mesozoic times of the ruling 
Dynasties in the life of their age ” (p. 385). 
1 On p. 29t Mesopitys is inadvertently included among genera with a double 
leaf-trace, cf. p, 296. 
