140 Boodle . — Spores in a Specimen of 
angular side. Figs. 2 and 3 represent internal views of 
spores in other positions. In some cases the pits and bars 
run uniformly, and all parallel, right across the spore. One 
spore is apparently not mature, having a smooth wall. 
There seems little doubt that the structures described above 
are spores, but it is as well to regard other possibilities. 
A group of short detached tracheides, such as one sees in 
the central region of the old stem of Isoetes , would present 
an appearance somewhat like that of the spore-mass in 
question, but the frequency of tetrahedral form is strongly 
in favour of their being spores, as is also the fact of their 
being so well preserved in a specimen from which the'xylem 
has disappeared. For, if they were tracheides, they would 
doubtless be lignified, and as liable to be destroyed as the 
xylem of the roots ; but spores, when strongly cuticularised, 
would be much more resistent to decay. 
Surrounding the group of spores there is a layer consisting 
of carbonaceous matter in the form of small cylindrical rods 
placed end to end, and running peripherally. These differ 
from the carbon masses in other parts of the section, and 
may possibly represent casts of cells belonging to an indusium, 
a sporangium-wall, or a tuft of hairs. 
Mr. Carruthers kindly pointed out to me the spores of 
Trochopteris elegans l , as most nearly resembling those de- 
scribed above, among living ferns. The thickenings in the 
spore-wall are very similar in the two cases. The spores 
are almost exactly of the same shape, and of the same 
average size, individual spores varying considerably. Though 
many spores of Trochopteris have their thickenings slightly 
differently arranged, e.g. more uniformly parallel, twisted 
at the angles of the spore, or more closely set, still certain 
spores have their pits and thickenings almost precisely as in 
Temp sky a ; thus one spore examined was a nearly exact 
counterpart of that shown in Fig. 1. 
1 Through the kindness of Mr. Carruthers I was enabled to examine the spores 
of Trochopteris, Cercitopteris, and other genera in the Herbarium of the British 
Museum. 
