IV.—STIGMARIA STRUCTURE.—By Henry S. Poote, F. B.S. C. 
KG] S386 
(Read March 18th, 1901.) 
The specimen of Stigmaria here exhibited is from the Coal 
Measures at Stellarton, and from a fireclay bed between two of 
the working coal seams. The original fragment, about 9 inches 
long and 3.5 by 2.25 in cross-section, was given to the Geological 
Survey Museum with a preferred right to a section should the 
piece ever be cut. This was done on the advice of the Director. 
the late Dr. Dawson, who also sent another section to Mr. 
Kidston of Stirling, Scotland. 
The special intrest in the specimen, lies in the exceptionally 
well preserved condition of the heart or medulla due to infiltration, 
the whole root having been converted into clay ironstone. The 
piece here shown presents a cross section only of the beautifully 
preserved scalariform tissue of the medulla which is placed below 
the centre of the root and nearest the concave underside. Mr. 
Kidston in his acknowledgment to Dr. Dawson, remarked that 
the section was one of considerable interest from a_ botanical 
point of view, shewing more numerous and finely radiating 
wedges of vascular tissue than other stigmaria roots he has lately 
been studying. 
Stigmaria, when first found, were considered a distinct genus 
but are now known to be but the roots of Sigillaria. The late 
Mr. R. Brown of Sydney Mines, Cape Breton, found in the cliffs 
near the pits a tree trunk that clearly showed the passage of the 
Sigillaria stem into the Stigmaria roots, and similar specimens 
have been found elsewhere. 
The Sigillaria, Mr. Carruthers describes as consisting of a 
central cellular pith or medulla surrounded by a sheath consist- 
ing wholly of scalariform vessels, the whole enveloped in an 
(345) 
