PRESENT POSITION OF PALEOZOIC BOTANY—SCOTT. 403 
easily be confounded, in the detached condition, with this Cordaitean 
seed. The resemblance of the seeds of Pecopteris Pluckeneti, Anei- 
mites, and (I believe) Hremopteris to those of the Cordaitee is a 
striking fact, showing that the bilateral or radial symmetry of the 
seed is of no value as a means of distinction between this Gymno- 
spermous family and the Pteridosperms. 
No paleobotanical discovery would be more interesting at the pres- 
ent time than that of the anatomical structure of Pecopteris Pluche- 
neti. The species is not typical of its genus, and was placed by 
Sterzel in a distinct genus, Dicksoniites, on account of his discovery 
of bodies which he interpreted as sori, and compared to those of 
Dicksonia; their nature is not yet clearly understood. 
SYSTEMATIC POSITION OF THE PTERIDOSPERME#, 
The name Cycadofilices designated a group, only known at the time 
by its vegetative characters, which hovered in the gap between Fili- 
cinee and Cycadophyta without showing any decided leanings to 
either side. The class name Pteridospermez represents a more ad- 
vanced stage in our knowledge, and indicates plants which we know 
to have been already definitely Spermophytic, though retaining many 
marks of a Filicinean origin. This consideration appears suflicient 
to justify the institution of the new class. 
The question remains, whether the Pteridosperms should be in- 
cluded under Gymnosperms or kept apart, at least for the present, as 
a subkingdom of their own. Many botanists will doubtless follow 
Professor Zeiller in choosing the former alternative. Personally, I 
incline to the latter, for reasons which I will now state. The ques- 
tion, it may be said at once, is largely one of convenience, for there 
can be no doubt of the Gymnospermous affinities of the group under 
discussion. So far as the seed is concerned, the Pteridosperms were 
Gymnosperms, on the same level with the Cordaitez. The only con- 
stant peculiarity of the seed is a negative one, the absence of an em- 
bryo, and this is common to the Cordaitez, which in all other respects 
were as highly organized as recent Gymnosperms. 
If the Pteridospermez are to be kept distinct it must be on other 
grounds. The chief characters are the following: 
1. The fact that the seeds were borne on fronds but little modified, 
as compared with the vegetative foliage. This appears to have been 
the case in every Pteridosperm where we have any evidence on the 
subject, and affords an important character, though a female Cycas 
no doubt only differs in degree. 
2. The male organs. Like the female, they appear to have been 
borne on ordinary fronds, and, if we may judge from the one case 
