GEOLOGY. 231 



tion, it was exposed to the action of the waves on the coast. The 

 sparing dissemination of grain gold through the drift affords an- 

 other argument in favor of the su-pra-marine theory. 



In Australia the most important deposits of alluvial gold have 

 been found in valleys immediately above the bed rock, beneath 

 beds of gravel and clay; and much richer deep sinkings have 

 been discovered in the vicinity of surface washings, a seem- 

 ingly necessary result of the sorting arrangement of water. In 

 Nova Scotia, though denuded auriferous quartz lodes are abun- 

 dant, no similar deposits have been found ; the gold is either dis- 

 tributed throughout the superficial deposits, or occurs in greatest 

 abundance at the surface. In Australia the denuding agent was 

 water, which carried off the ground-up rocks, but left the gold 

 behind. In Nova Scotia the denuding agent was glacier ice, which 

 carried off both the stony masses and their metallic contents. 

 The drift beds left contain only the same proportion of gold as 

 existed in the original rocky mass, excepting where aerial denu- 

 dation has concentrated it on the surface. 



AGE OF THE "TRAIL" AND THE " WARP." 



Rev. O. Fisher, in the "Geological Magazine," May, 1867, 

 maintains that the palasolithic period was more ancient than the 

 formation of the "trail, "and formed some part of the interval 

 between 100,000 and 200,000 years before A. D. 1800. Then, af- 

 ter the glacial era of the trail, followed a period of equable sea- 

 sons, of about 80,000 years 1 duration, which would have been that 

 of the submarine forests and their occupants. After this came 

 the period of the warp, a short period of severe winter cold; and, 

 finally, the period of the last submergence of our valleys had 

 passed away about 8,000 years ago. 



CANADIAN FLORA. 



According to Dr. Dawson, who has published in the " Canadian 

 Naturalist " a list of some of the plants found in the Leda-clay 

 deposit, on the Ottawa, the species found are the most hardy 

 ones of the present flora. He shows that this is not an accidental 

 selection, nor due to the river bringing refuse from more northern 

 latitudes. He infers from this that there has been refrigeration, a 

 fact which seems borne out by what would occur were the land 

 again submerged to the extent that it was at the time of the depo- 

 sition of the Leda clay ; a climate like that of Labrador would 

 be the result. 



ANCIENT VEGETATION OF NORTH AMERICA. 



At a meeting of the Lyceum of Natural History, in New York, 

 in May, 1867, Prof. Newberry presented a paper on the above 

 subject. The most important facts cited were as follows : 



Vegetables only have the power to assimilate inorganic sub- 

 stances in nature, the animal kingdom being wholly dependent 

 on the vegetable for its subsistence, and could not exist without 



