314 FEENS : BEITISU AND FOREIGN. 



and other genera^ the roots are naturally of a dark, or 

 even quite black colour, and it is known to have been 

 considered by some cultivators, not well versed in the 

 nature of Ferns, as dead, and accordingly they are totally 

 removed, even although with evidence of the plant 

 being healthy and vigorous. The healthy state of the 

 plant is readily explained, for on examining the nume- 

 rous points of the black roots,, each will be seen to be 

 of a pale colour, which are the active feeders of the 

 plant ; and, in shifting, great care should be taken not 

 to bruise or injure them. 



The same directions apply to the gigantic Tree 

 Ferns and species of Angiopteris. The soil for them, 

 however, should be of a coarser nature when of a size 

 to I'equire the largest-sized pots or tubs ; in no case 

 is it desirable to give more than three inches extra 

 space at one shift, even in the largest pot or tub. In all 

 pots above one foot in diameter, the drainage should 

 be elevated in the centre. When the shift is large, an 

 inverted pot should be placed in the new pot, placing 

 a layer of drainage round it, the height of the pot to 

 be such that the crocks of the old ball (which must 

 not be taken out) rest on the top of the new drainage 

 or pot. By this the outer circle of bottom roots are 

 not pressed together, or crushed by the weight of the 

 ball, which is sure to be the case when the ball is set 

 on a level surface, it also keeps the ball to its proper 

 height. This mode of drainage has been the constant 

 practice at Kew with all large shifts, not only for Ferns 

 but ProteaceoB and all fine fibrous-rooted plants, the 

 nature of which is to extend outwards and downwards 

 through the new soil, ultimately forming a web of 

 roots against the sides of the pot. In the ordinary 



