254 
PROFESSOR W. C. WILLIAMSON ON THE ORGANIZATION 
long) it is always a much more oblong seed than is the case with T. olivceforme. How 
far any specific distinctions can be ascertained from these internal casts of seeds, apart 
from structure, is extremely doubtful. 
The next seeds which I have to describe are those which have long been known by 
Brongniart’s name of Cardiocarpus. Until recently we were only familiar with the 
external aspect of various forms and sizes of these seeds, disconnected from their stems. 
At length the discovery, by Mr. Peach, of some specimens described and figured by Mr. 
Caeruthers * exhibited these seeds in such connexion with the plants known as Antho- 
lithes as to leave no doubt that the latter are the racemose peduncles, on the secondary 
peduncles of which some species of these seeds were supported. But it is obvious that 
Antliolithes is not the only form assumed by the peduncles of these fruits. Professor 
Newberry figures one f where the seeds are sessile on a long straight peduncle, and Dr. 
Dawson figures a small fragment $ in which the seeds are similarly arranged; only here 
each seed is supported upon a short solitary peduncle, devoid of the surrounding 
appendages characteristic of Antliolithes. 
The genus Cardiocarpon was established by Brongnjart, in his ‘Prodrome,’ in 1827, 
for the reception of “ Fruits comprimes lenticulaires, cordiformes ou reniformes, ter- 
mines par un pointe peu aigue” (loc. cit. p. 87). Oddly enough, his later ‘Tableau’ 
contains no notice of it as a distinct genus, but he refers to the seed as probably belong- 
ing to the Noeggerathise. 
All the writers who followed Brongniart have spoken of these objects as fruits. In 
his memoir on the Devonian plants just quoted Dr. Dawson examined these supposed 
fruits, and “ arrived at the conclusion that the Cardiocarpa of the type of C. cornutum 
were Gymnospermous seeds , having two cotyledons imbedded in an albumen, and covered 
with a strong membranous or woody tegmen, surrounded by a fleshy outer coat, and 
that the notch at the apex represents the foramen or micropyle of the ovule ” (loc. cit. 
p. 61). In the same memoir (p. 62) Dr. Dawson further remarks : — “ Though I have 
no doubt that the above is the correct interpretation of C. cornutum, I do not regard it 
as applicable to all Cardiocarpa .” Mr. Carruthers, in his later memoir, referred to 
above, speaks of them as fruits invested by a pericarp. 
I need scarcely say that this question of seeds versus fruits cannot be easily settled, in 
the case of the fossil examples, so long as Botanists hold such widely divergent view 7 s on 
the same question in relation to the reproductive organs of living Gymnosperms. Whilst 
Eichler contends that the seeds of Conifers are really gymnospermous, and Strasburger 
thinks otherwise, it must obviously be difficult to decide the question in the case of 
fossil forms detached from most of their surrounding organs. 
Professor Newberry has figured in his work already quoted a fine series of Cardiocarpa 
from the Carboniferous deposits of Ohio, but none of these display any definite internal 
* “ Rotes on some Fossil Plants,” Geol. Mag. yol. ix. no. 2, Feb. 1872. 
t ‘ Geol. Survey of Ohio/ pi. xli. fig. 4. 
} ‘ Fossil Plants of the Devonian and Upper-Silurian Formations of Canada/ pi. xix. fig. 227, a. 
