54? A MANUAL OF FORESTRY. 



thicker in the case of loose or dry soil, and thinner in 

 firm or wet soil. 



The seed of different species requires a different 

 covering. On the whole, large seeds such as acorns 

 and chestnuts, require the thickest covering ; consider- 

 ably less, the seeds of Beech, Maple, Hornbeam, Silver 

 Fir ; less again, those of Alder, Ash, Scotch Pine, 

 Spruce, and Larch ; least, those of Elm and Birch. 



According to experiments made by Baur* on loamy 

 sand the best results were obtained with coverings of 

 the following thickness : 



English Oak . . . . 1'50 inches. 



Beech ...... -75 ,, 



Sycamore and Silver Eir . . '60 ,, 



Scotch Pine and Spruce . . . "50 ,, 



Common Alder .... "40 ,, 



Larch ...... '35 ,, 



Elm -12 



The seed can be covered in various ways, by 

 ploughing (in the case of acorns), harrowing, raking, 

 light hoeing, or by scattering fine earth over it. 



d. Sprouting of the Seed. 



During germination the rootlet is first developed, and 

 then the stem ; as soon as the latter breaks through the 

 surface of the soil, the seed is said to sprout. A few 

 European species, such as Oak, Sweet Chestnut and 

 Hazel, leave their cotyledons below the surface, but the 

 majority bring them above ground. 



* Professor of Forestry at the University of Munich. 



