XVIl] STIGMAEIOPSIS 237 



tap-roots. Grand'Eury's conclusions are briefly as follows : 

 Sigillaria, and we may add Lepidodendron, had no true roots 

 and in this respect are comparable with Psilotum (fig. 118): 

 the organs which are described by Grand'Eury as roots are 

 correctly so named in a physiological sense, but morphologically 

 they do not strictly conform, either in origin or in the arrange- 

 ment of their appendages, to true roots. The question as to 

 whether they are entitled to the designation root is one which 

 it is needless and indeed futile to discuss in detail ; it would be 

 conceding too much to a formal academic standpoint to refrain 

 from applying to them the term root, as that best describes 

 their share in the life of the Sigillarian stems. The horizontal 

 Stigmarian axes are rhizomes in the ordinary sense of the term 

 and from these were developed Sigillarian shoots, characterised 



Fio. 209. Stigmariopsis and "tap-roots." (After Grand'Eury.) 



in the lower portions by large parichnos strands. From 

 the base of the young bulbous shoots roots were formed : these 

 roots being, in the French specimens, of the Stigmariojjsis type. 

 These conclusions require some modification when applied 

 to British representatives of the arborescent Lycopodiales. 

 The long spreading and dichotomously branched root-like organs 

 attached to the base of Sigillarian and Lepidodendron stems 

 are true examples of Stigmaria ficoides or other species. Stig- 

 mariopsis occurs but rarely. This marked difference between 

 French and English specimens may be explained if we adopt 

 the opinion of Solms-Laubach, who believes that the true 

 Stigmaria represents both the parent rhizome and the later- 

 formed roots of the Rhytidolepis Sigillarian species and of 



