ii2 STUDIES IN FOSSIL BOTANY 



structure enables us to clearly understand the organisa- 

 tion of Sphenophyllaceous strobili. Specimens preserved 

 only as carbonaceous impressions may, however, afford 



Fig. 47. — Sphenophyllum fertile. Diagram A. Node in radial section, showing one 

 sporophyll. z/./., ventral lobe ; v.s. } a ventral sporangiophore bearing two sporangia ; 

 r'.s'., stump of another sporangiophore; d.l., d.s., d.s'., corresponding dorsal parts. 

 B. one lobe of sporophyll, as seen in a transverse section of the cone ; ax, axis. On 

 two of the sporangiophores a sporangium is shown. From Scott, Phil. Trans. 



suggestive indications, and suffice to show that, within 

 the limits of what we call the genus Sphenophyllum, there 

 must have been great variety in the fructification. In 

 S. majus, for example, the impressions of the lax fertile 



