88 Proceedings of the Royal Physical Society. 



Dawson, on the other hand, in his memoir "On Spore 

 Cases in Coal," ^ which may be regarded as a reply to the 

 conclusions arrived at hy Huxley, believes that it is only 

 under exceptional circumstances that spores enter very largely 

 into the formation of coal. 



Though not entering into this part of the subject, we are 

 inclined to accept Dawson's view of the part spores take in the 

 formation of coal. From our experience, when spores occur 

 in any great quantity in coal, they are usually restricted to 

 narrow bands, from an inch to two inches in thickness, and 

 though spores may be detected throughout the whole seam, 

 still the part taken by them in the formation of coal gener- 

 ally (excepting the spore bands already referred to) seems 

 small when compared with the other vegetable remains 

 which enter into its composition. 



Such spore bands in coal are, however, common in Scot- 

 land. 



A paper on the subject by Mr E. Wethered appeared in 

 the Journ. Boy. Mic. Soc. for 1885,^ where figures are given 

 of spore coals from various localities, one plate (PL IX.) being 

 devoted to the illustration of the splint coal from Whitehill 

 Colliery, Eosewell, Midlothian.^ 



It next falls to be considered what plants produced these 

 fossil macrospores. 



We have already referred to the macrospores described by 

 Professor Morris from the cone of a species of Zepidodendron. 

 Many of the cones containing micro- and macrospores, de- 

 scribed by Binney and others, also most probably belong to 

 Zepidodendron. But spores similar in character to those 

 discovered in the cones of Zepidodendron have likewise been 

 found in the cones of Sigillaricc. In 1855, Goldenberg 



1 Annals and Mag. Nat, Hist., vol. vii., p. 321, 1871. 



2 2d ser., vol. ii. 



s See also Wethered, On the Occurrence of Spores of Plants in the Lower 

 Limestone Shales of the Forest of Dean Coal Field, and in the Black Shales of 

 Ohio, United States— Cotteswold Naturalists' Field Club, 1884. 



Note. — The Trigonocarpus Sporitcs, Weiss, Foss. Flora d. jiing. Stk. u. d. 

 Roth. Zweites Heft, 1871, p. 204, PL XVIIL, Figs. 22, 23, are most probably 

 Lycopodiaceous macruspores. 



