774 Notes . 
Lepidodendron i) or the greater part ( Tmesipteris ) of the primary wood 
is centripetal. 
The Calamite which forms the subject of the present communica- 
tion occurs in the well-known Burntisland beds of the Calciferous 
Sandstone Series, at the base of the Carboniferous Formation. The 
material is calcified, and the structure excellently preserved, though 
the specimens so far discovered are small and fragmentary. Their 
interest depends on the fact that each vascular bundle possesses a 
distinct arc of centripetal wood on the side towards the pith. The 
carinal canals are present, as in an ordinary Calamite, and contain, as 
usual, the remains of the disorganized protoxylem. They do not, 
however, as in other Equisetales, form the inner limit of the wood, 
but xylem of a considerable thickness, and consisting of typical 
tracheides, extends into the pith on the inner side of the canal, which 
is thus completely enclosed by the wood. Hence, starting from the 
spiral tracheides of the protoxylem, there was here a considerable 
development of xylem in a centripetal as well as in a centrifugal 
direction. That the organ was a stem, and not a root, is proved, not 
only by the presence of the carinal canals, but by the occurrence of 
nodes, at which the outgoing leaf-traces are clearly seen. 
This appears to be the first case of centripetal wood observed in 
a Calamarian stem, and thus serves to furnish a new link between the 
Palaeozoic Equisetales and the Sphenophyllales, and through them 
with the Lycopods. 
The specimens have not as yet supplied any evidence as to the 
superposition or alternation of the verticils, so we are not at present in 
a position to determine the genus to which they belonged. Pro- 
visionally, until further investigation has cleared up this question, the 
new stem may bear the name of Catamites petty cur ensis, from the 
locality where it occurs. 
D. H. SCOTT. 
Kew. 
REMARKS UPON THE NATURE OP THE STELE OP 
EQUISETUM 1 . — The vascular bundles of Equisetum are usually 
compared with those of a monostelic Phanerogam both in structural 
detail and with regard to their course out into the leaf. The following 
1 Abstract of paper read before the Botanical Section of the British Association, 
Glasgow, September, 1901. 
