H. C. SOKBY ON A COAL-MEASURE FOREST. 459 



the subjacent clay-like shale are not of a nature suitable for the pre- 

 servation of minute markings ; and it is only just possible so to 

 recognize the Sigillarian character of the trunks and the Stigmarian 

 markings on the roots as to feel certain that they are Sigillarice. 

 Their general characters will be seen from the following drawing 

 of the largest and best-preserved specimen (fig. 2). It is about 



Fig. 2. — Fossil Stump of Sigillaria at Wadsley near Sheffield. 

 (Scale i inch to 1 foot.) 



5 feet 2 inches in diameter, with almost as flat a surface as if it had 

 been cut off with a saw. There are eight large roots, which when 

 exposed are seen to bifurcate and extend in some directions for 

 about 6 feet, after which they are either hidden or have been de- 

 stroyed, so that their total length is unknown. By the side of this 

 stump is a large prostrate trunk, as shown in the figure. These 

 specimens are enclosed in one of the sheds. The total number of 

 stumps which were exposed was about ten, spread over a distance 

 of 40 or 50 yards. All that can be properly seen have either eight 

 roots when the stump is large, or only four when small and par- 

 tially grown, which agrees with what has been previously observed 

 in similar cases. Two fine specimens occurring near together have 

 been covered by a single larger shed. 



What appears to me to be one of the most interesting facts con- 

 nected with' these trees is the evidence they furnish with respect to 

 the direction of the prevailing winds at the time when they grew. 

 A careful examination of the trees now growing on the exposed 

 moorland hills of the district shows that when they are young the 

 prevailing westerly gales often make them incline towards the east ; 

 and in doing this, the roots on the west side are pulled straight and 

 made to run more horizontally, whilst those on the east side are 

 pressed down and made more nearly vertical ; and these characters 

 remain permanently when the tree has grown to a large size. Now 

 this sort of difference on different sides can be recognized more or 

 less decidedly in the case of all the stumps seen in the "Wadsley 

 fossil forest, but is especially well marked in the largest and best- 

 preserved specimen (fig. 2) ; and it appears to me a very interesting 

 fact that the direction of the prevailing high winds at the Carbo- 

 niferous period thus indicated is almost exactly the same as that at 

 the present period, as shown by the same facts seen in trees now 

 growing in the neighbourhood. 



