Catamites and Dicotyledons . 139 
the nodal region of tangential sections of Calamitean wood, 
and at first interpreted by him as branches, are in reality 
leaf-traces, that the figures mentioned above are correctly 
orientated in their original position. 
Another apparent reason for inverting the figures of tan- 
gential sections through the wood of Calamites was derived 
from the statement made by M. Renault, that certain organs 
occurring below the leaf-traces in the secondary wood bore 
roots. These organs he called ‘ organes rhiziferes,’ and iden- 
tified them with Williamson’s infranodal canals. If they were 
rhizophorous, it appeared to the writer that they could not 
well be other than reduced radiciferous branches, homologous 
with those of living Equiseta. In the Equiseta both the normal 
branches and the rhizophorous ones have the same relation 
to the leaf-traces, and the conclusion seemed warranted that 
the leaf-traces should lie above the normal branches of 
Calamites in the secondary wood, as well as above the organs 
described by M. Renault as rhizophorous. 
Obviously, the argument in the last paragraph turns on 
whether the ‘organes rhiziferes’ of M. Renault (infranodal 
canals of Williamson) were really radiciferous or not. Through 
the kindness of Dr. D. H. Scott the writer has had the oppor- 
tunity of studying two beautiful series of tangential sections 
through bases of Calamitean branches bearing roots. Such 
specimens are extremely rare. An examination of the series 
showed that the roots were not attached to the infranodal 
organs, although the latter were present in abundance. The 
writer owes to the courtesy of M. Renault the opportunity 
of examining the Calamitean sections in the collections of 
the Jardin des Plantes. Although some of the preparations 
showed roots imbedded in the secondary wood, the writer 
was unable to discover that in any case they were related 
to infranodal organs. M. Renault’s statement that roots 
were attached to the infranodal organs possibly depends on 
the observation of Weiss, that the infranodal tubercles are 
absent on the medullary casts of aerial portions of Calamites. 
Grand’Eury also, in one of his older articles on Calamites, 
