3- 



STUDIES IN FOSSIL BOTANY 



came to exactly the same conclusion independently, 

 from the study of the French material. These observa- 

 tions show that very often the small lateral branches 



I [(). g.-Calamites communis. Tangential section of wood, passing through a node as 

 in Ftg. S, but showing the base of a branch, inserted between and above two of 'the 

 leaf-trace bundles, f, vascular bundles of stem ; m, leaf-traces ; c, medullary rays 

 X 20. After Williamson, Phit. Trans, Will. Coll. 90. 



were cast off early, a fact which admits of two ex- 

 planations. The branch may either have been abortive 

 altogether, or, which is still more likely, it may have been 

 caducous, forming a limited shoot of temporary duration, 



