No. 2.] NOTES ON PROTOTAXITES. J^"' H^. 



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

 yews. I may further say that Mr. Carruthers' figure is in my 

 judgment to a great extent imaginary. 



But what 0^ the arrangement of these fibres. It is true thaty. 

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

 cell, and I hesitated to account for this appearance. The 

 possibilities of such an appearance, as yet, perhaps, uuknown. 

 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 t<> 

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

 of cells. I have good examples in the Mesozoic Taxoxyloa. 

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

 often entirely destroyed, and only the ligneous lining remains,, 

 perhaps thickened by incrustation of mineral matter within. la 

 this case the original lining of the cell uiay seem to be an exter- 

 nal structure. I have examples both in Mesozoic conifers and ia 

 carboniferous plants. Long soaking in water and decay have 

 thus often made what may have been a lining of wood-cells appear 

 as an intercellular matter, or an external thickening of the walls.„ 

 (3.) In decayed woods the mycelium of fungi often wanders 

 through the tissues in a manner very perplexing; and I suspect^ 

 though I cannot be certain of this, that some fossil woods have 

 been disorganized in this way. At the time when my descrip- 

 tion was published. I felt uncertain to which of these causes to 

 attribute the peculiar appearance of Prototaxites. I have now,^. 

 from subsequent study of the cretaceous Taxineae of British 

 Columbia,* little hesitation in adopting the first and second ex- 

 planations, or one of them, as probable. 



Mr. Carruthers does not believe in the medullary rays of Proto- 

 taxites. The evidence of these is the occurrence of regular lenti- 

 cular spaces in the tangential section, which appear as radiating^ 

 lines in the transverse section. The tissues have perished; but 

 some tissues must have occupied these spaces ; and in fossil woods 

 the medullary rays have often been removed by decay, as one 

 sometimes sees to be the case with modern woods in a partially 

 decayed state. Mr. Carruthers shoujd have been more cautious 

 in this matter, after his rash denial, on similar grounds, of me- 



* Report of Geol. Survey of Canada, now in course of publication^ 

 The collections contain wood showing the structure of yew, cypresSj., 

 oak, birch, and poplar, all irom rotks of cretaceous age. 



