n8 



ANCIENT PLANTS 



cases they are glandular, as is seen in g in fig. 79, and 

 as they seem to be unique in their appearance they have 

 been of great service in the identification of the various 

 isolated organs of the plant. 



As is seen from fig. 77, the leaves were quite fern- 

 like, but in structural specimens they have been found 

 with the characteristic glandular hairs of the plant. 



The seeds were 

 so long known under 

 the name of Lageno- 

 stoina that they are 

 still called by it, 

 they have 



though 



been identified 



as 



belonging to Lygino- 

 dendron. They were 

 small (about \ in. 

 in maximum length) 

 when compared with 

 those of most other 

 plants of the group, 

 or of the Cycads, 

 with which they show 

 considerable affinity. 

 They are too com- 

 plex to describe fully, 

 and have been men- 

 tioned already (see 



p. 76), so that they will not be described in much detail 

 here. The diagrammatic figure (fig. 56) shows the 

 essential characters of their longitudinal section, and 

 their transverse section, as illustrated in fig. 80, shows 

 the complex and elaborate mechanism of the apex. 



Round the "seed" was a sheath, something like the 

 husk round a hazel nut, which appears to have had 

 the function of a protective organ, though what its real 

 morphological nature may have been is as yet an un- 

 solved problem. On the sheath were glandular hairs 



Fig. 79. Transverse Section through Petiole of 

 Lyginodendron 



v, Fern-like stele ; c, cortex ; g, glandular hairlike 

 protuberances. 



