174 THE CANADIAN NATURALIST. [Vol. vii^ 



Mr. C, after describing Prototaxites according to his own 

 TiewB of its BtructurCj expresses the opinion that "the merest 

 tyro in histological botany " may see that the plant could not be 

 phaenogamous. JBut if the said tyro will take tho^trouble to refer 

 to the beautiful memoir on the Devonian of Thuridigia, by Richter 

 and Unger,* and to study the figures and descriptions of Apor- 

 oxylon prhnigenlum,^ Stigmaria annular is^Calamopter is dehUisy. 

 and Calamo»yrinx Deconlciis^ he will find that there are Devonian 

 plants referred by those eminent palaeontologists to Gymnosperms 

 and higher Cryptogams, which fall as far short of Mr. Carruthers*' 

 standard as Prototaxites itself. Nothing can be more fallacious 

 in fossil botany than compariwns which overlook the structures 

 of those primitive palaeozoic trees which in so many interesting 

 ways connect our modern gymnosperms with the cryptogams. 



It is scarcely necessary to reply to such a statement as that 

 the fibres of Prototaxites have no visible terminations. They 

 are very long, no doubt, and both in this and their lax coherence 

 they conform to the type of the yews. In Mesozoic specimens of 

 Taxoxylon which I have now before me, the fibres are nearly ae 

 loosly attached and as round in cross section as in Prototaxites. 

 In these, as in Prototaxites, water-soakage has contributed to 

 make the naturally lax and tough yew-structure less compact, and 

 to produce that appearance of thickness of the walls of the fibres 

 which is so common in fossil woods. 



Disks or bordered pores in Prototaxites I did not insist on, 

 the appearance being somewhat obscure; but Mr. Carruthers 

 need not taunt me with affirming the existence of such pores in 

 the walls of cells not iu contact. Pores, if not bordered pores,, 

 may exist on such cells, and the wood cells of Prototaxites are in 

 contact in many places, as may easily be seen, and even where 

 they appear separate, this separation may be an effect of partial 

 decay of the tissues. 



Mr. Carruthers converts the spiral fibres lining the cells of 

 Prototaxites into tubes connecting the cells. This is a question 

 of fact and vision, and I can only say that to me they appear to 

 be solid, highly refracting fibres ; and under high powers, pre- 

 cisely similar to those of fossil specimens of Taxoxylon from 



* Trans., Vienna Academy, 1856. 



f I have elsewhere compared Aporoxylon with Prototaxites, 'Jour. 

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



