2i8 THE BOOK OF NATURE STUDY 



the level of the ground water remains permanently near the 

 surface. When this is the case a deposit of peat or peaty soil 

 will begin to accumulate, because the stagnant water cuts off 

 all supply of air from the soil. Thereupon the roots and other 

 vegetable debris begin to decay in an entirely different fashion 

 from that normally experienced by such material when in contact 

 with air, as may be seen by comparing a dead branch rotting 

 away on the surface of the ground in a wood with a similar branch 

 that has been buried many years in the mud of a pond. The black 

 humus material that forms from vegetable matter in the absence 

 of air is generally acid in character, and is accompanied by a deposit 

 of oxide of iron, which in peaty boggy land forms a thin film over 

 the water of the ditches and stains their banks with rust. Con- 

 siderations of space will not allow of any detailed account of the 

 flora of peaty and boggy land, but a student should attempt 

 to discriminate between the flora cf the acid true peat soils and 

 the mild peaty or boggy areas occurring where the water is 

 naturally charged with carbonate of lime. 



THE PRINCIPLES OF CULTIVATION 



In the cultivation of the land the prime object of both farmer 

 and gardener is the preparation of a good seed bed, but what 

 constitutes a good seed bed is easier perhaps to feel than to define. 

 It should consist of some five or six inches of friable, mellow 

 soil, naturally worked down into fine grains. It should rest on a 

 firm basis and be compact in itself, because it contains neither 

 rough unbroken clods nor large vacant spaces. On any but 

 the lightest soils the preparation of a seed bed must begin 

 before the winter, by ploughing or digging up the ground so 

 as to leave it in a rough state to the action of the successive 

 frosts and thaws. Even during this preliminary work strong 

 land should not be moved nor trampled upon when it is wet, 

 otherwise the clay gets into the puddled or tempered condition, 

 whereupon it remains very sticky when wet and dries into hard 

 clods. The subsoil as well as the soil should be moved, when- 

 ever the expense can be faced ; but on most soils care should 

 be taken only to stir the subsoil without bringing it up to 



