158 ANCIENT PLANTS 



of the stalk, as in fig. 117, si. As the stalk was long 

 and slender, but a short length of it is usually cut through 

 in any one section, and to realize their mode of attach- 

 ment to the axis (as shown in fig. 116) it is necessary to 

 study a series of sections. 



Of the other plants belonging to the group, Bow- 

 manites Romeri is specially interesting. Its sporangia 



sp 



Fig. 117. — Part of Cone of Sphenophyllum^ showing sporangia sp, some of whidi 

 are cut so as to show a part of their stallts st. E, Bract. (Microphoto. ) 



were borne on stalks similar to those of Sphenophyllum, 

 but each stalk had two sporangia attached to it. Two 

 sporangia are also borne on each stalk in 5. fertile. 

 These plants help in elucidating the nature of the stalked 

 sporangia of Sphenophyllum, for they seem to indicate a 

 direct comparison between them and the sporophylls of 

 the Equisetales. 



There is, further, another plant, of which we only 

 know the cone, of still greater importance. This cone 



