Johnstone: The Ancestors of the Angtosperms. 339 
appearance that, until their connection with Lygtnodendron was 
recently established by Mr. Kidston,* they were regarded as the 
sporangia of a true fern; but that, in strong contrast to all 
these, it bore remarkably complex seeds, evolved apparently 
long before anything approximating to a flower was in existence 
in this group. + 
It is, however, from Mesozoic times that we get types more 
closely allied to our existing forms. As a result of the study 
of these, a new family has been constituted—the Bennettite@— 
which includes, besides the true Cycadales, those species which 
combine the habit of growth and the foliage of Cycads with a 
fructification differing absolutely from that of any known plant. 
The type genus was founded in 1868 by Mr. Carruthers} to 
include species from the Middle Oolites to the Lower Greensand. 
In their general appearance, in the mode of attachment of the 
remarkable fruits to the plant axis, and in their detailed 
structure the English specimens agree so closely with American 
species (to be referred to below) that the same description may 
suffice for both. 
Another allied form was obtained from the Lower Oolite of 
Yorkshire ; this was the Zama gigas, of which an account was 
presented by Williamson in 1868, and which was placed by 
Mr. Carruthers in the new genus W7//‘amsonia. The fructifi- 
cations found with the Zamza-like foliage of this plant, were 
very puzzling, exhibiting externally a globular form clothed 
with bracts, and internally a disk-like structure bearing a 
pyramidal upgrowth. Dr. Wieland’s recent work strengthens 
the view expressed by Mr. Seward that these plants were 
allied to the Bennettites. 
But by far the most important of recent discoveries are 
those of Dr. Wieland.§ These, the results of eight years’ 
labour, are embodied in a magnificent volume published last 
year on ‘American Fossil Cycads.’ The wealth of material 
which has been at Dr. Wieland’s disposal has been obtained 
from the Mesozoic beds of America, ranging from Upper Trias 
to Lower Cretaceous horizons: its classification has been the 
work of Professor Lester Ward. 
It is these Bennettitee (Cycadoidee of Wieland) which seem 
to furnish the key to the evolutionary problem of the angio- 
* Kidston, Trans. Royal Soc. (1905). 
+ Oliver and Scott, Trans. Roy. Soc. (1904). 
+ Carruthers, Trans. Linn. Soc. xxvi. (1868). 
§ Wieland, American Fossil Cycads (1906). 
1907 October 1. 
