Zoology and Botany. 331 



coast is 200 miles broad in the Carolinas ; becomes still broader in 

 Georgia, and, sweeping round the northern extremity of the chain, 

 joins the valley of th& Mississippi. This strip influences the distri- 

 bution of animal life, by extending southerly to the 5° of latitude, 

 thus forming also a barrier to the progress of anadromous fish from 

 the Atlantic to the bottom of the Gulf of Mexico. With refe- 

 rence to physical geography, Newfoundland appears as a pro- 

 longation of the Atlantic coast line, and its zoological and botanical 

 productions correspond to those of Labrador. When the canals al- 

 ready projected shall have opened a communication between the 

 several great inland seas which exist in North America, an inter- 

 change will take place between the fish of widely diverging waters. 

 The great proportion of water to land forms a striking feature of 

 the north-east continent. This may be zoologically divided into 

 two districts, viz. the northern or barren grounds, and the southern 

 or wooded. The temperature is here materially influenced by the 

 inland sea of Hudson's Straits, and thus its capability of supporting 

 animal life much aftected. On the west of the Rocky Mountains, 

 the northern corner appears to be similar to the eastern side or 

 barren grounds. The general character of the country bordering the 

 Pacific is mountainous. With respect to the climate of North Ame- 

 rica, the eastern coast has a lower mean temperature than the western, 

 at least in the higher latitudes. Probably the isothermal, and even 

 the isothseral lines of the banks of the Columbia and New Cale- 

 donia correspond nearly in latitude with those of the east coast of 

 Europe. But on the eastern side, down to the 56th parallel of 

 latitude, the subsoil is perpetually frozen. Even in the 45th pai'al- 

 lel, on the north side of the great Canada lakes, there is upwards of 

 six months of continuous frost, and the grallatorial and most of the 

 graminivorous birds can find nothing to support them in the winter 

 season ; and, consequently, the migration of the feathered tribes is 

 here much more general than in the countries of Eui'ope lying un- 

 der the same parallel. The principal cause of this great difference 

 between the climates of the eastern and western districts may be 

 ascribed to the configuration of the coast land, which detains the ice 

 in its bays and gulfs, and this, in melting, materially depresses the 

 summer heat. The decrement in the mean annual heat, correspond- 

 ing to the increase in latitude, is greater in North America than in 

 Europe, and there exists a wider difference between the tempera- 

 tures of summer and winter. Dr Richardson then concluded this 

 introductory portion of his report, by details concerning the tempe- 



