THE 



GEOLOGICAL MAGAZINE. 



No. LXI.— JULY, 1869. 



L — The Crtptogamio Forests of the Coal Period. 

 By "William Carruthers, F.L.S., F.G.S., of the British Museum.^ 



THE student of fossil botany encounters greater difficulties in his 

 efforts to restore the vegetation of former epochs in the earth's 

 history, than those which beset the labours of the comparative 

 anatomist in his restoration of extinct animals. These difficulties 

 arise chiefly from two causes : First, the absence in the vegetable 

 kingdom of a substance which would resist decay like the solid 

 skeleton found in all the vertebrate, and in many of the invertebrate 

 members of the animal kingdom, causes the fragments of plants 

 which have escaped decomposition to be preserved much less perfectly 

 than the remains of animals. Carbonaceous stains or amorphous 

 casts are the most frequent indications (^f the former vegetation of 

 the globe ; specimens exhibiting structure are comparatively rare ; 

 and it is such specimens only that give certain evidence of the nature 

 and affinities of the organisms to which they belong. 



The other serious source of difficulty arises from the fact that no 

 relative proportions exist among the different parts of a vegetable 

 individual. The size of the leaf, the flower, or the fruit, can give no 

 indication of the size of the plant. Indeed, these are more frequently 

 found large in humble plants which never rise above the surface of 

 the ground than in large trees. And this is true, not only in the 

 general, but even among members of the same natural group ; where 

 great differences exist in tlie size of the individuals, no corresponding 

 differences are to be found in the parts of whicli they are composed. 

 Thus the foliage and fruit of our tmly indigenous pine — the Scotch 

 fir — are greater than those of the mammoth Wellingionia of California ; 

 and the fruit of the small willow fSalix herhacea, L.), which covers 

 with a dense carpet the summits of some of the higher mountains of 

 Scotland, is as large as that of the huge willows which ornament the 

 margins of our English rivers. On the other hand, the different parts 

 of an animal possess such relations to each other in size, form, and 



1 Being the suhstance of a lectui'e delivered before the Royal Institution of Great 

 Britain, at the Weekly Evening Meeting on Friday, April 16, 1869, Sir Henry 

 Holland, Bart., M.D. D C.L. F.R.S., President, in "the Cliair. The Illus:rationa 

 have been kindly lent by the Council, together with permission to reprint this 

 valuable contribution to Fossil Botany. — Edit. 



VOL. VI. — MO. LXI. 19 



