a 



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

 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 

 Taxoxyhn which I have now before me, the fibres are nearly as 

 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 uffirniing the existence of such pores in 

 the walls of cells not in 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 lininj^ 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 

 British Columbia, and to those seen in charred slices of modern 

 yews. I may further say that Mr. Carruthers' figure (Plate 

 XXXII.) is in my judgment to a great extent imaginary. 



But what of the arrangement of these fibres. It is true that, 

 as I have stated, they appear in some cases to pass from cell tp 

 cell, and I hesitated to account for this appearance. Mr. C. 

 might, however, have spared himself the remark that " if Dr. 

 Dawson knew anything whatever about a vegetable cell, and the 

 formation of the spiral fibre in its interior, he would not have 

 written such nonsense" — (a specimen, by the way, of the ameni- 

 ties of British Museum Science, as represented by Mr. C.) 

 The possibilities of such an appearance, as yet, perhaps, unknown 

 in the plant-rooms of the Museum, result from the following con- 

 siderations: (1.) In more or less crushed fossil plants, it is not 

 unusual to see what are really internal structures appearing to 

 pass beyond the limits of the cell-wall, from the mere overlapping 

 of cells. I have good examples in the Mesozoic Taxoxylon 

 already mentioned. (2.) In fossil woods the original cell-wall is 



