BT CUITINGS OF IMMATURE GEOWTHS. 161 



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

 immature parts of plants. Sand, burnt clay or pnlyer- 

 ized brick, charcoal, peat. Sphagnum moss, and yarious 

 combiaations of these and other materials, have been 

 employed by propagators ; and -while any one, or aU of 

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

 delicate the cutting, and difiBcnlt 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 free from all 

 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 may be used with safety, if well washed 

 to remove the oxides of iron and other metals which are 

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

 other shades of color. "When ordinary building or pit- 

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

 dug out and exposed to the weather for a few weeks or 

 months previous, in order to hasten the further oxidizing 

 of the metals which it may contain, and facilitate their 

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

 such purposes, besides it contains various salts, 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 sand in which to place his 

 cuttings. 

 If pure sand is placed in pots, boxes or frames, with 



