58 
PROFESSOR W. C. WILLIAMSON ON THE ORGANIZATION 
drawing represents the specimen of the size of nature, but I am convinced that it was 
originally much longer than now. My cabinet contains two other fragments, which I 
believe belonged to it; but whether they did or not, the specimen is obviously 
broken off abruptly at each end. As it is, we have seven verticils of pedunculated 
strobili, two or three of which strobili only appear on the surface of the shale at each node. 
That this fructification has belonged to a different species of Aster ophyllites to Plate V. 
fig. 31, appears from the fact that in the former all the strobili were pedunculate, whilst 
in the latter most of the lateral ones are sessile. In this respect the latter plant seems to 
resemble the Annularia densifolia figured by Eichwald*, which also agrees with the 
Brooksbottom type in the presence of verticils of very distinct scars, marking the points 
from whence strobili have been detached. Fig. 32 appears to be very similar to the 
pedunculated fruit originally figured by Sternberg under the name of VolJcmannia 
polystachia. The Sphenopliyllites Schlotheimi of Germar f is also of the same type. 
In my specimen each slender peduncle is about *37 in length. It is slightly thickened 
where it springs from a node of the central axis, and still more so as it enters the 
strobilus. It obviously consists of a single joint or internode. The principal axis (Ic) 
consists of a series of long internodes, most of which range between IT and T2 in length, 
and which are delicately but distinctly striated longitudinally ; at each node this axis 
enlarges somewhat into a small lenticular disk, and attached to several of these we 
observe isolated leaves of Asteropliyllites, constituting in each case the leaf from the 
axil of which the adjacent strobilus has sprung. Each strobilus consists of a linear 
series of verticils of bractigerous disks, disposed at intervals of about T25. Each disk 
on leaving the axis first curves somewhat downwards, and then upwards and outwards. 
The marginal fringe of bracts continues in the latter course, so that their tips stand out 
free, as in A. Dawsoni, instead of coming into close contact with the next superior verticil. 
Each of these bractigerous disks sustains a stratum of sporangia upon its upper surface. 
The exact arrangement of the latter cannot be ascertained with accuracy ; but I am quite 
satisfied that they are disposed, as in A. Dawsoni, in more than one concentric ring. 
'‘Neither have I been able to determine with absolute certainty the exact number of 
bracts in each verticil ; but it is obviously about fifteen or sixteen, which is a rather 
smaller number than in A. Dawsoni. 
The preceding facts suffice to show that whilst various authors have figured different 
modifications of a common type of Asterophyllitean fruits, none of them obtained any 
clue to the internal organization of that type. A. Dawsoni has given us that clue. 
Secondary modifications have doubtless existed amongst the various species ; but that 
the external forms and the inward organization of these fruits of Asteropliyllites and 
Sph enophy l him are now substantially correlated is a fact about which I entertain no 
doubt. 
An important question still seeks an answer, viz. What is Calamostachys Binneyana \ 
Mr. Binney and Mr. Carruthers both reply, it is the fruit of a Calamite. But my 
* Lethcea Rossica, tab. xv. fig. 8. f Steinkohlen-Gebirges von Wettin und Lobejiin, tab. vi. 
