CANADIAN PLEISTOCENE FLOliA AND FAUNA. 337 



identical with species now common in the same district — except, of course 

 Zostera — thus indicating similar climatic conditions. 



At Gi-een's Creek, near Ottawa, and at Besserer's Wharf, a few miles 

 below on the Ottawa River, numerous plant remains are found enclosed 

 in clay nodules, but their very fragmentary character often renders their 

 determination most unsatisfactory. These two localities, although sepa- 

 rately treated, are in reality one and the same, since the deposit at each 

 place is of the same nature, and was undoubtedly laid down at the same 

 time, and they have proved to be among the richest in plant remains of 

 all the localities studied — no less than twenty-eight species havin"' been 

 recovered from the clay nodules. An analysis of this flora shows 

 35-71 per cent, of the plants to be wholly aquatic, and therefore deposited 

 in place. 35"71 per cent, are land plants, drifted in by tributary rivers, 

 and 28*57 per cent, represent semi-aquatics and marsh plants from adjacent 

 land areas. The vegetation, as a whole, is identical with that now found 

 in the same i-egion, from which we may infer similar climatic conditions. 



At Scarborough Heights, near Toronto, the flora is rather remarkable 

 for the complete absence of aquatic types, showing the drift character of 

 the entire deposit. Fourteen species in all have been found there, and of 

 these six are trees, while the remaining eight embrace mosses, equiseta, 

 and herbaceous or half-shrubby plants. The vegetation as a whole is of 

 a decidedly more boreal type than that now flourishing in the same region, 

 and, if anything, somewhat more northern than that which is to be found 

 in the deposits at Green's Creek and Montreal. This points to a climate 

 equivalent to that of northern Quebec and Labrador, as we know it 

 to-day, and somewhat colder than the climate at Green's Creek and 

 Montreal during Pleistocene time. 



In the Don Valley no less than eight separate localities have been 

 examined. Some of them, as at Simpson's, proved practically ban-en of 

 results so far as plant remains were concerned, owing to the uncontrollable 

 influx of water. Others again, as at Taylor's Brickyard and the Don 

 River, proved to be exceptionally rich in material, and afforded some of the 

 most valuable results obtained. Within this area no less that thirty-ei«ht 

 species have been recovered, and they point conclusively to the existence of 

 climatic conditions diff"ering materially from those which now prevail, and of 

 a character more nearly allied to that of the middle United States of to-day. 



The Erie Clays at Hamilton, Ontario, have afforded only one example 

 of plant life, and this does not materially aid us in any conclusions relative 

 to climatic conditions, since it is a type having a somewhat wide ran^e 

 within the warmer zone, represented by the more southern types of the 

 Pleistocene flora. 



Only one species appears to have disappeared in Pleistocene time. Acer 

 pleistocenicum, which was abundant in the region of the Don, bears no 

 well-defined resemblance to existing species. With this one exception, it 

 is a noteworthy fact that all the plants of the Pleistocene flora were such 

 as are now represented in the same localities, or, in the case of the Don 

 Valley, by plants which find the northern limits of their distribution at or 

 near that region, and the somewhat unequal distribution thus indicated 

 at once suggests definite climatic changes during Pleistocene time, as 

 represented by the northern and southern migration of particular types of 

 plants. This has already been referred to in previous reports and publi 

 cations, but it may be repeated at this time that the definite and abundant 

 occurrence of JIaclura aurantiaca, Jimiperun virr/iniana, Quercux obtusi- 

 lUOO. ' r 



