lOO 



HARD WICKE'S SCIENCE- G OS SI P. 



it in the hollow stem of a plant, which accounts for its 

 peculiarly good state of preservation. The specimen 

 was about six inches in length and nearly an inch in 

 diameter. One end of the cone was rounded and 

 marked with the small imbricated leaf scars which 

 pertain to these fruits, while the other end was con- 

 tinuous with the branch, a portion of which was 

 attached. This specimen illustrates the manner in 

 which many of these lepidostrobi were formed, 

 viz., by a thickening of the terminal end of a 

 branch. 



For many years I preserved this beautiful and rare 

 cone in niy cabinet intact, being afraid of cutting it 

 up for fear that it would, like most of its fellows, show 



The thorn-like fossil known under the name of 

 halonia, was formerly taken to be the root of lepido- 

 dendron, but Professor W. C. Williamson has shown, 

 as the result of a very careful examination and dissec- 

 tion of a number of specimens of Halonia, that the 

 knob-like projections so peculiar to this plant 

 had their origin in the bark and not in the pith as 

 they would have done had they been the bases of 

 rootlets. He therefore came eady to the conclusion 

 that Halonia was a fruit-bearing branch of lepido- 

 dendron. 



Some time after this conclusion was arrived at, a 

 lepidodendron was found which bifurcated into two 

 branches in the usual way, but while one of them 



Fig. 65. — Transverse section oi Lepidodendroii selaginoides (magnified). 



no internal structure, but at length yielding to the 

 urgent solicitations of a dear brother " chip" I com- 

 mitted it to the untender mercies of the diamond 

 wheel, a sacrifice which I soon regretted, for it turned 

 out as I expected it would do, to be far more beauti- 

 ful externally than internally. Upon cutting it open 

 I found that its original internal structure was gone, 

 with the exception of a portion of the central axis, 

 and here and there a bract that had originally borne 

 sporangia. But sporangia and spores were gone 

 and their places were filled with yellow iron pyrites, 

 one of the worst substitutes that could possibly 

 have been found, from a micro-lapidary point of 



view. 



bore the same markings as the parent stem, the other 

 was a true halonia, thus confirming the conclusion 

 which Professor W. C. Williamson had already 

 arrived at. 



Much controversy has taken place concerning the 

 nature of ulodendron. This most singular but beau- 

 tiful fossil is distinguished by having two rows, one 

 on each side of the stem, of large round scars which 

 are placed close together and running the whole 

 length of the stem. These scars had always been 

 understood as being the bases of cones, but a few 

 years ago Mr. Carruthers, F.R.S., gave a description 

 of Ulodendron, in which he described the scars as 

 the bases of aerial roots which descended to the 



