144 



THE GEOLOGICAL HISTORY 0?' PLANTf. 



■5 3 



"This difference is not less striking when we reduce 

 the above centesimal analyses to correspond with the 

 formula of cellulose, 0241120020, and represent cork and 

 Lycopodium as containing twenty-four equivalents of 

 carbon. For comparison I give the composition of speci- 

 mens of peat, brown coal, lignite, and bituminous coal :* 



Cellulose CaJI.joOao 



Cork (!.«H,„V>«i^ 



Lyeopodiuni ('a4lIiBi'uN0&i'\j 



Peat (Vaux) Ca^IIwVVOio 



Brown coal (Sehrothcr) C24I1i4|',tO,oi''() , 



Lignite (Vaux) CaiHui'^irOniV 



I3i*uminous coal (Repnault) CaillioOai'o 



**It will be seen from tliis comparison that, in ulti- 

 mate composition, cork and Lycopodium are nearer to 

 lignite than to woody fibre, and may be converted into 

 coal with far loss loss of carbon and hydrogen than the 

 latter. They in fact ajjproach closer in composition to 

 resins and fats than to wood, and, moreover, like tlioso 

 substances repel water, with which they are not easily 

 moistened, and thus ai ~ able to resist those atmospheric 

 influences which effect tlie decay of woody tissue." 



I would add to this only one further consideration. 

 The nitrogen present in the Lycopodium s{)()res, no doubt, 

 belongs to the protoplasm contained in tliem, a substance 

 which would soon perish by decay ; and subtracting this, 

 the cell-walls of the spores and the walls of the sporc- 



♦ " Canadian Naturalist," vi., 253. 



