246 ELEMENTS OF SYLVICULTURE. 



moreover, it ought not to be grown pure, and it is 

 by the method in question that its natural auxiliaries 

 are associated with it. The alder renders the same 

 service in moist and wet lands ; it grows rapidly, and 

 yields valuable produce at an early age. 



CHAPTEK IV. 



SLIPS* AND LAYERS, 



STOCKING with slips and layers cannot, properly 

 speaking, be termed operations of sylviculture, but 

 rather of horticulture. Nevertheless slipping is pre- 

 ferred to sowing in the propagation of willows and 

 poplars (excluding of course the great sallow and 

 the aspen), to keep up pretty varieties, to reproduce 

 exotics, which are not completely naturalised, like 

 the plane tree, &c. The method of layers is still less 

 used, and could scarcely possess any utility in forests 

 except to re-stock small blanks. In nearly every 

 case planting is to be preferred. 



There are two methods of slipping : stake slipping, 

 and slipping with two year old wood. 



The first succeeds well only with the large willow, 

 theosier, &c. The stake consists of a branch three 

 or four yards long and about two inches in diameter. 

 It is stripped of all its branches, and cut obliquely at 

 both ends, or at least at its lower end. By this means 

 a larger surface of absorption is obtained, and success 

 is favoured. To put ifc into the ground, a hole about 

 20 inches deep is made with a spade, or, in wet soil, 

 * See footnote on page 204. 



