ANCIENT PLANTS 



have mentioned, and, with their fleshy coat, were similar 

 in general organization to the Cycads, though the fact 

 that the seed coat stood free from the inner tissues right 

 down to the base seems to mark them as being more 

 primitive (cf fig. 55, p. 76). 



Of impressions of the Pteridosperms the most striking 

 is, perhaps, the foliage known as , , 



Neuropteris (see fig. 6, p. 13), to « /' 

 which the large seeds are found 

 actually attached (cf fig. 85). 



— n 



Fig. 84. — Diagrammatic Section of 

 a Transverse Section of a Seed of 

 Trigonocarpus 



s, Stone of coat with tliree main 

 ridges and six minor ones. F, Flesh 

 of coat ; if, inner flesh ; //, nucellus, 

 crushed and free from coat; s, spore 



wall. 



Fig. 85. — Fragment of 

 Foliage of Neuropteris 

 with Seed attached, show- 

 ing the manner in which 

 the seeds grew on the 

 normal foliage leaves in 

 the Pteridosperms 



Ever- increasing numbers of the "ferns" are being 

 recognized as belonging to the Pteridosperms, but 

 Heterangium, Lyginodendron, and Medullosa form the 

 three principal genera, and are in themselves a series 

 indicating the connection between the fernlike and Cy- 

 cadean characters. 



Before the fructifications were suspected of being 

 seeds the anatomy of these plants was known, and 



