44 STIGMARIA FICOIDES. 



Knorria and Lepidodendron." It is needless to add that all these cases only point 

 to the fact that the Lepidodendra had Stigmarian roots as well as the Sigillarise. 



This abundance of Stigmarise apart from SigillariaB has been referred to by 

 more than one writer as a proof that Stigmaria was sometimes an independent 

 plant sui generis. The reply is obvious. We have abundant proof that, wherever 

 we obtain a Stigmaria connected with any aerial appendage, that Stigmaria is always 

 in the position of a root ; and seeing that all the other fragments referred to have 

 precisely the same characteristics of form and structure as those roots, we 

 have the strongest a priori ground for believing that they too were roots ; any- 

 how, until the opposite view is demonstrated to be probable by more conclusive 

 evidence than has yet been discovered, deductive reasoning from what we do know 

 to be facts compels us to infer that true Stigmarias were always roots. 



