American institute. 383 



are not clean cut these annual sprouts soon become a bushy second 

 growth. Euiying grounds enclosed and left to nature become a 

 matted thicket. Wherever villages are planted on the western 

 prairies trees grow thriftily, and I can only account for these great 

 national meadows by supposing that the fires which run over them 

 annually in their wild condition destroy tlie young trees. 



Whatever may be the origin of the germs that are wanting in 

 the soil, for the conditions of vegetation there are always enough 

 of them present, and those wdiich are best adapted to the soil, by 

 more vigorous growth, ovei shadow and extinguish the others and 

 appropriate the whole ground to themselves. Thus in the great 

 plan of nature, the right growth occurs on the right soil ; and 

 this also, the best indication that we yet have of the nature of a 

 soil, is the character oi the plants that thrive on it. 



In the original distribution of the forest trees of this country, 

 the nature of the soil was indicated by the character of the timber. 

 The soft w^oods, poor in ashes, such as the coniferous evergreens, 

 occupied the poorer lands, while the hardier woods, rich in asiies, 

 like the maple and the beech, grew in better soil. So w^ell was 

 this know^n to the early settlers as to affect the price of lands; 

 and many farms to this day are affected by the designation and 

 value thus given them. 



By successive vegetations progressing from lower to higher 

 forms, nature has converted the barren tace of this continent into 

 alluvial surface-. One natural order of that progression is from 

 mosses and lichens by the way of wood sorrel and wintergreen to 

 wild grasses, and thence through briars to a stinted growth of 

 pine and other coniferae, to be follow^ed by hard wood, decidua. 

 Used in this way a crop for pine may doubtless be made of ser- 

 vice in a very long rotation to bind togetlier the moving sands 

 and form soil for higher organizations ; but the second growth of 

 this timber has not yet been fit to be used to any extent for 

 building purposes. It is stunted, hard and knotty when com- 

 pared with the gigantic trunks of tlie primitive stock — trunks 

 that run up free from limbs a single shaft for sixty feet or more, 

 and must have required as shown by the concentric rings, centu- 

 ries for development. 



In this progression the soft wood evergreens occupy a position 

 inferior to the hard wood deciduous trees. When the "hemlock" 

 or Canada spruce is once destroyed it is never restored, but its 

 place is occupied by a growth of beech and maple. The condition 

 of the soil in which ils germs originally vegetated has been so 

 changed that higher organizations by a more vigorous growth 



