54 
Lang.—Studies in the Ophioglossaceae. III. 
Photos 47-49. Separation of a leaf-trace from a stele of a small medullated rhizome of adult 
type. The trace is endarch at origin (Photo 47); the outer xylem becomes completed adaxially, 
while the trace is still monarch (Photo 48) ; and the trace later passes through the clepsydroid 
stage (Photo 49). x 67. 
Photo 50. Stele of the same rhizome as Photo 48, at a level nearer to the apex, showing the con¬ 
densation in size and structure, x 67. 
Photo 51. Stele of a small adult rhizome, showing a departing leaf-trace, the xylem of which 
becomes adaxially completed before separation from that of the stele, x 67. 
Photo 52. Stele of the stime rhizome as that in Photo 51, but nearer to the apex, photographed 
to the same scale as Photo 51. The stele exhibits condensation or reduction to a purely juvenile 
type, with scattered tracheides of inner xylem in the undefined pith, x 67. 
Photo 53. Transverse section of the stele of a young plant somewhat behind the apex. The 
outline of the stele is evident in the procambial condition, and the first-formed tracheides are seen to 
occur both dorsally (It.) in relation to the youngest leaf-trace, and ventrally (px.v.) in relation to the 
lower purely cauline portion of the stele, x 67. 
