122 S0MMERS FLORA OF NOVA SCOTIA AND COLORADO. 



2ND AGENCY. 



We are familiar with water and ice as transporting agencies, 

 the former exercised in various ways, the latter as ice sheets in the 

 Bay of Fundy and the Gulf of St. Lawrence. In Alpine regions 

 ice in the form of glaciers is well known as a transporting agent. 



The deposits which we have been examining as a class, are known 

 by the names diluvium, drift. Parts of these are also distinguished 

 by the qualifying adjective, glacial (deposit). The striation is also 

 called glacial or glaciation, while others retain the term drift, e. g. 

 gravelly deposit. 



The term Diluvium refers us to early geology, when the deluge 

 of Scripture was regarded as the great cause that produced these 

 accumulations. This view is now, however, regarded as untenable. 



The term Drift refers to another early view, which is still main- 

 tained by some in reference to the gravelly deposit, — that the 

 northern hemisphere had been scoured by broad waters and currents 

 which had extensively transported material from north to south, and 

 left the banks of drift as monuments of the dreadful catastrophe. 



The banks and their derivations, with the striation which we 

 have been examining, are .distinguished as glacial, and bring us to 

 existing views and disturbances, the agency being da, respectively, 

 ice sheets, ice bergs, and glaciers. Heretofore in the field of our 

 observation we have been dealing with incontrovertible facts, now we 

 meet with in our field, controvertible opinions, — we meet with the 

 advocates of ice sheets, and icebergs. 



(To be continued.) 



Art. II. — On a Correspondence between the Flora of 

 Nova Scotia, and that of Colorado, and the 

 Adjacent Territories. By. John Sommers, M.D., 

 Prof, of Physiology in the Halifax Medical College. 



{Read before the Institute of JVatural Science, Feb. 14, 1876.) 



While engaged recently in looking through a Synopsis of the 

 Flora of Colorado and the adjacent Territories, appended to the 



