526 REPORT— 1898. 



of the vegetation and climate of the Don period, but it lias extended our 

 knowledge of the flora in important directions. 



(a) Frcu/ments of Wood. — With few exceptions the wood occurs in 

 fragments — either mere splinters or pieces of branches — and they show 

 not only more or less extended decay, but the external appearance indi- 

 cates the rather prolonged action of water. This appears in the rounded 

 and worn surfaces and angles, and suggests that the material may have 

 been transported for some distance by river, or that it was thrown upon 

 a beach and then subjected to the prolonged action of waves. In no case 

 has the silicification of the structure been carried very far. All the woods 

 so far studied cut readily with a saw, they soften with ease in boiling 

 water— in a few cases only requiring the addition of sodium carbonate — 

 and the sections are subsequently cut on an ordinary microtome. Altera- 

 tions due to the extreme effect of decay and subsequent pressure are 

 common, but in most cases have been of such a nature as to permit a 

 recognition of the genus. 



While in many cases decay has progressed so far as to make the genus 

 or species recognisable with difficulty — sometimes not at all — in other 

 cases the same species may be preserved with remarkable perfection, so 

 that all the features of the internal structure may be distinguished as in 

 a piece of wood freshly cut from a living tree. In one case (Juniperus 

 vii-giniana) the preservation was so perfect that the original coloiir of the 

 wood was suggested by the external appearance ; a radial fracture showed 

 the characteristic aspect of the medullary rays ; the shredded bark was 

 recognisable, and, when cut with a saw, a perceptible odour of cedar was 

 noticed. External characters are rarely preserved to such an extent.; but 

 one other case (Madura aurantiaca) merits notice, in that the presence of 

 perfectly preserved spines — in some cases half-buried in an overgrowth of 

 wood — served abundantly to confirm previous conclusions drawn from the 

 internal structure alone. In nearly all the Pleistocene woods thus far 

 brought under observation it has been found that in those cases in which 

 decay has not been carried to an extreme the various species acquire 

 certain well-defined external characters whereby it is possible to distin- 

 guish them without microscopic examination. The species studied during 

 the year are as follows, and from the localities indicated : ' — 



Taijlor^s Brickyard, Don Valley. 



Platanus occidentalis, Linn. 

 jVIaclura aurantiaca, Nutt. 

 Larix americana, Michx. 

 *Juniperus virginiana, Linn. 



Price's Brickyard, Don Valley. 



Larix americana, Michx. 

 ■*Pinus strobus (1), Linn. 



Gaol Hill, Don, Valley. 

 *Juniperus virginiana, Linn. 

 Madura aurantiaca, Nutt. 

 *Quercus rubra (?), Linn. 

 ■*Quercus alba (?), Linn. 



' The * denotes, in tbis and the succeeding pages, species additional to those 

 of the previous list, the f thxt they are new to the locality. 



