has been preserved. I am indebted to Dr. T. Sterry Hunt for the following very valuable information, which at once places in a clear and precise light the chemical relations of epidermal tissue and spores with coal. Dr. Hunt says: "The outer bark of the cork-tree, and the cuticle of many if not all other plants, consists of a highly carbonaceous matter, to which the name of _suberin_ has been given. The spores of _Lycopodium_ also approach to this substance in composition, as will be seen by the following, one of two analyses by Duconi,[CJ] along with which I give the theoretical composition of pure cellulose or woody fibre, according to Payen and Mitscherlich, and an analysis of the suberin of cork, from _Quercus suber_, from which the ash and 2·5 per cent of cellulose have been deducted.[CK] [CJ] Liebig and Kopp, "Jahresbuch," 1847-'48. [CK] Gmelin, "Handbook," xv., 145. ---------+-----------+--------+------------ | Cellulose.| Cork. | Lycopodium. ---------+-----------+--------+------------ Carbon | 44·44 | 65·73 | 64·80 Hydrogen | 6·17 | 8·33 | 8·73 Nitrogen | .... | 1·50 | 6·18 Oxygen | 49·39 | 24·44 | 20·29 +-----------+--------+------------ Total | 100·00 | 100·00 | 100·00 ---------+-----------+--------+------------ "This difference is not less striking when we reduce the above centesimal analyses to correspond with the formula of cellulose, C{24}H{20}O{20}, and represent cork and _Lycopodium_ as containing twenty-four equivalents of carbon. For comparison I give the composition of specimens of peat, brown coal, lignite, and bituminous coal:[CL] [CL] "Canadian Naturalist," vi., 253. Cellulose C{24}H{20}O{20} Cork C{24}H{18-2/10}O{6-7/10} Lycopodium C{24}H{19-4/10}NO{5-6/10} Peat (Vaux) C{24}H{14-4/10}O{10} Brown coal (Schröther) C{24}H{14-3/10}O{10-6/10} Lignite (Vaux) C{24}H{11-3/10}O{6-4/10} Bituminous coal (Regnault) C{24}H{10}O{3-3/10} "It will be seen from this comparison that, in ultimate composition, cork and _Lycopodium_ are nearer to lignite than to woody fibre, and may be converted into coal with far less loss of carbon and hydrogen than the latter. They in fact approach closer in composition to resins and fats than to wood, and, moreover, like those substances repel water, with which they are not easily moistened, and thus are able to resist those atmospheric influences which effect the decay of woody tissue."