Palaeontoiogk-. 143 



centrifugal in development, as in Stigmaria ficoides. The woocl 

 is interrupted by large medullary rays which also cxtend through 

 the phloem-region, which is fairly wcli preserved. 



The cortical tissues are of great thickness and excellently 

 preserved throughout, where as in most specimens of Stigmaria 

 the middle cortex is missing. The inner cortex is only five 

 or six cells in thickness, but the middle zone is very massive, 

 its parenchyma sometimes presenting the appearance of inter- 

 woven filaments, as in the stem of Lepidophloios. This zone 

 shows indications of secondary growth around the rootlet-bundles 

 which traverse it, and which are here accompanied by a sheath 

 of cells continuous with the inner cortex. 



The large-celled outer cortex is bounded superficially by a 

 band of periderm, below which distinct groups of secreting 

 tissue are present, as described by Seward in Lepidophloios 

 fiiliginosus and Harcourtii. 



The rootlets, as shown on the external surface of the 

 specimen, were quincuncially arranged. In their structure, and 

 their relation to the stele and cortex they agree essentially with 

 the well-known monarch appendages of Stigmaria. The sugges- 

 ted identification of the fossil with Lepidophloios fiiliginosus, is 

 based chiefly on the small development of the secondary wood, 

 and on the characters of the middle cortex, the presence of 

 secretory tissue beneath the periderm strengthening this identi- 

 fication. 



The Stigmarian rootlet, described in the second part of 

 the paper, is regarded as probably closely connected with 

 Xenophyton and therefore with Lepidophloios fiiliginosus. The 

 whole thickness of the cortex is preserved — an unusual 

 condition in these organs; the middle zone has the same felted 

 character as in the plants just mentioned; in its externa! layers 

 it shows centrifugal secondary growth. The stele has the usual 

 monarch character. 



The most interesting feature of the rootlet is the presence 

 of a row of tracheides, enclosed in a sheath, and running 

 horizontally from the protoxylem of the stele into the cortex, 

 where, apparently, a more vertical course was assumed. The 

 author regards this Strand as identical with the vascular 

 branches described by Renault in Stigmarian appendages, 

 an Observation hitherto unconfirmed. This question is dealt 

 with more fully in the paper abstracted below. 



D. H. Scott (Kevv). 



Weiss, F. E., The Vascular Branches of Stigmarian 

 Rootlets. (Annais of Botany. Vol. XVI. 1902." p. 559 

 —573. PI. XXV!.) 



Renault, in 1881 described and figured rootlets of 

 Stigmaria in which a delicate vascular Strand was given off 



