104 THE EVOLUTION OF PLANTS 



various, more or less fragmentary remains which 

 belonged to Lyginodendron, so as to gain a con- 

 nected view of the whole plant, has been a slow 

 process; the foliage was described as long ago 

 as 1829; the male organs, the last part to be 

 recognised, not till 1905. We will not, however, 

 follow historically the stages of reconstruction, 

 but will briefly give the results as they now 

 stand. 



Lyginodendron oldhamium, a plant of the 

 Lower and Middle Coal Measures, has been 

 described as a little Tree-fern in habit; the 

 stem was long and slender, seldom reaching two 

 inches in diameter. It is possible that it may 

 not have been upright, and that it supported 

 itself with the help of stronger neighbours; the 

 presence of spines all over the stem and leaves, 

 like those on the climbing fronds of the West 

 Indian Bramble Fern (Davallia aculeata), has 

 suggested this idea; on the other hand there 

 are small upright Tree-ferns, such as a Fijian 

 species of Todea, with which the fossil plant 

 might also be compared. In many specimens 

 the stem was freely branched, but it is doubtful 

 whether this was always the case; indeed it is 

 quite possible that several distinct species may 

 be grouped under the collective name Lyginoden- 

 dron oldhamium. 



The foliage consisted of very large and beau- 



