124 



HARDWICKE'S SCIENCE-GOSSIP. 



be compared with the ancient sigillaria. Its external 

 appearance may be roughly compared to one of our 

 large, straight pine-trees shorn of its branches, and 

 in their places the upper part was thickly studded 



of this strange plant, and about its true position"in 

 the vegetable kingdom, for notwithstanding the vast 

 number of specimens of portions of its trunk and 

 of its roots (stigmaria) extant, yet the true form (or 



Fig. 76. — Sigillaria vascularis (Diagrammatic section). | 



i 14. 77- — Sm.'ill segment of 

 fig. 76, magnified 80 dia- 

 meters, showing form and 

 arrangement of vessels 

 and cells. 



M-ith long, narrow leaves, while the lower part was 

 1 are, but richly ornamented along the ridges with the 

 markings left by the fallen leaves. There has been 

 considerable discussion concerning the morphology 



Fig. 78. — Sigillaria Tascularts (showing 

 medullary pith and ligneous zone). 



forms) of the terminal portion of the stem is still 

 unknown. 



Some species are supposed to have had a crown 

 of fern-like fronds after the manner of our modern 

 tree-ferns. But this is not supported by facts, no^ 

 such fern-like fronds having ever been found .actually 

 attached to sigillaria. Other species are supposed 

 to have borne branches, these branches having been 

 formed in the peculiar manner called by botanists 



