RemarJcs on Mr. Carruihers' Views of PrototaxUes. 67 



1. Mode of Occurrence. — This alone should suffice to convince 

 any practical palaeontologist that the plant cannot be a sea-weed. 

 Its large dimensions, one specimen found at Gaspe Bay being three 

 feet in diameter; its sending forth strong lateral branches, and 

 gnarled roots ; its occurrence with land plants in beds where there 

 are no marine organisms, and which must have been deposited in 

 water too shallow to render possible the existence of the large 

 oceanic Algae to which Mr, Carruthers likens the plant. These are 

 all conditions requiring us to suppose that the plant grew on the 

 land. Further, the trunks are preserved in sandstone, retaining 

 their rotundity of form, even when prostrate ; and are thoroughly 

 penetrated with silica except the thin coaly bark. Not only are 

 Algae incapable of occurring in this way, but even the less dense and 

 durable land plants, as Sigillarise and Lepidodendra are never found 

 thus preserved. Only the extremely durable trunks of coniferous 

 trees are capable of preservation under such circumstances. In the 

 very beds in which these trees occur, Lepidodendra, tree-ferns and 

 Psilophijton are flattened into mere coaly films. This absolutely 

 proves, to anyone having experience in the mode of occurrence of 

 fossil plants, that here we have to deal with a strong and durable 

 woody plant. 



These considerations were dwelt on in my published descriptions 

 of Prototaxites, but they naturally have more weight in my judg- 

 ment than in that of Mr. Carruthers. Geologists and palaeologists 

 at least will be able to appreciate them. 



2. Microscopic Structure. — It would be tedious to go into the 

 numerous scarcely relevant points which Mr. Carruthers raises on 

 this subject. I may say in general that his errors arise from neglect 

 to observe that he has to deal not with a recent but a fossil wood, 

 that this wood belongs to a time when very generalized and humble 

 types of gymnosperms existed, that the affinities of the plant are to 

 be sought with Taxineae, and especially with fossil Taxineae, rather 

 than with ordinary pines. 



Mr. C, after describing Prototaxites according to his own views 

 of its structure, expresses the opinion that " the merest tyro in his- 

 tological botany " may see that the plant could not be phaenogamous. 

 But if the said tyro will take the trouble to refer to the beautiful 

 memoir on the Devonian of Thuringia, by Eichter and linger,* and 

 to study the figures and descriptions of Aporoxylon primigenium,\ 

 Stigmaria annularis, Calamopteris dehilis, and Calamosijrinx 

 Devonicus, he will find that there are Devonian plants referred by 

 these eminent palaeontologists to gymnosperms and higher Cryp- 

 togams, which fall as far short of Mr. Carruthers' standard as Proto- 



• Trans., Vienna Academy, 185G. 



t I have elsewhere compared Aporoxylon with Prototaxites, ' Journal Geol. 

 Soc.,' 1862, p. 306. Report on Devonian plants. 



VOL. X. G 



