HARDWICKE'S SCIENCE-GOSSIP. 



273 



very good ones from the marine strata overlying the 

 Hahfax hard bed coal. 



Description of the diagrams. 



Fig. 150 is a diagram of an ordinary sandstone cast 

 of Sternbergia, showing the peculiar transverse mark- 

 ings of the fossil. 



Fig. 151 is a transverse section of Dadoxylon with 

 the tissues preserved, with the exception of the bark, 

 which is absent, as it is in the great majority of speci- 

 mens. The transverse section of the ligneous zone 

 shows a regular network arrantrement of the vessels 



probably a specific difference between them. In 

 many of the transverse sections the annular rings of 

 growth are plainly visible : one of my specimens, 

 which is less than an inch in diameter, shows five or 

 six of them. 



The pith, when any is preserved, is seen to be a 

 regularly-formed parenchyma of very delicate struc- 

 ture, and composed of hexagonal cells. Many of 

 my sections show a portion of this structure, but it is 

 generally very much disintegrated, and only detached 

 portions are preserved. 



Fig. 151. — Dadoxylon (magnified 4 diams.\ transverse section. From a specimen in the Author's collection. 



which are square and as regular as a woven fabric, 

 and the finest meshes of gossamer silk fabrics are 

 coarse and ugly compared to them. The longitudinal 

 section of these tissues shows a series of long tube-like 

 vessels which are marked with pitted disks, just the 

 same as those which characterise the living pines. 

 The medullary rays may be seen crossing these vessels 

 in a very interrupted manner, also in the same way 

 that they do in recent species. There are many 

 specimens of Dadoxylon which do not show the 

 pitted disks, but have the vessels reticulated, this is 



In comparing the structure of the fossil pines with 

 that of their modern representatives, we shall not fail 

 to observe the very close affinity which exists between 

 them, and as we know that structure is very much 

 modified by surrounding conditions, we may reason- 

 ably infer that the habitats of the ancient carboni- 

 ferous pines was similar in a general way to those 

 which recent pines seem to prefer, namely upland 

 districts. There are other collateral evidences which 

 also point to the same conclusion, such as the fact 

 that all specimens of this genus bear evidence of 



