STRUCTURE OF FOSSIL PLANTS 



67 



modern plants (see Chap. VII), and there are to be 

 found vascular arrangements no longer extant. 



When we turn to the Reproductive Organs, we find 

 that the points of like- 

 ness between the living 

 and the fossil forms 



A B 



Fig. 45. Fern Sporangia 

 A, fossil; B, living. 



are not so numerous 

 or so direct as they 

 are in the case of the 

 vegetative system. 



As has been indi- 

 cated, the families of 

 plants typical of the 



Coal Measures were not those which are the most 

 prominent to-day, but belonged to the lower series of 

 Pteridophytes. In their simpler forms the fructifications 

 then and now resemble 



each other very closely, B 



but in the more ela- A 

 borate developments 

 the points of variety 

 are more striking, so 

 that they will be dealt 

 with in the following- 

 chapter. Cases of like- 

 ness are seen in the 

 sporangia of ferns, 

 some of which appear 

 to have been practi- 

 cally identical with 

 those now living. 



/-pi . . .-i-i i Fig. 46. A, Living Lycopod cone; B, Lepidoden- 



[ niS IS Illustrated in dron ( fossil ) cone> a< Axis . Si scale . S| sporangium 



fig. 45, which shoWS with spores. One side of a longitudinal section 



the outline of the cells 



of the sporangia of living and fossil side by side. 



In the general structure also of the cones of the 

 simpler types of Lepidodendron (fossil, see frontispiece) 

 there is a close agreement with the living Lycopods, 



