BY CUTTINGS OF IMMATURE GROWTHS. 161 



used, in which to root cuttincrs made of the green and 

 immature parts of plant-. $fu->[. burnt clay or pulver- 

 ized brick7~chareoal, peat, Sphagnum nooss, and various 

 combinations of these and other materials, have been 

 employed by propagators ; and while any one, or all of 

 them, may sometimes answer the purpose, still, the. more 

 delicate the cutting, and difficult the plant is to propa- 

 gate in this way, the purer must be the material in which 

 the cuttings are set to insure the production of roots. In 

 a previous chapter I have shown that the exposed cells of 

 a branch or leaf taken from certain plants will imbibe 

 various poisons and colored liquids presented to them, 

 which are successfully resisted by the roots of the same 

 plant ; consequently, the material best and safest to use 

 in growing green cuttings in general is one f i^jjfronx^ill, 

 salts, metallic oxides, humus or coloring matter of any 

 kind. The most abundant and available material of this 

 nature is pure silex (sand). That which maybe obtained 

 from the banks of fresh water streams, ponds and lakes 

 is generally the purest and best, but that found in the 

 ordinary .sand-pit niay be used with safety, if well washed 

 to remove the^)xi^esor"Tron and other metals "wnTch. are 

 usually present, giving to the sand its red, yellow, or 

 other shades of -Qolor., When ordinary building or pit- 

 sand is to be used lor propagating plants, it should be 

 dug out^an^expo^ed to the weather for^jej^we^ks or 

 months previous, in order to hasten tKeTfurther oxidizing 

 of the metals which it may contain, and facilitate their 

 removal by washing. Sea-sand is, as a rule, too line for 

 such purposes, besides it contains various saljjs, and fre- 

 quently magnetic iron in large quantities. Many a gar- 

 dener has sustained serious losses from attempting to 

 propagate certain kinds of plants, through negligence in 

 this matter of obtaining pure ,san(l in which to place his 

 cuUings. 



iFpure^ sand is placed in pots, boxes or frames, with 



