198 Principles of Plant Culture. 
plum, raspberry, blackberry, juneberry, etc., often form both 
buds and rootlets by spring, so that they may be planted 
directly in the open ground. Those of more tender species, 
as the bouvardia, geranium, etc., will not start to the same 
degree, unless placed in the propagating bed toward spring 
and given bottom heat. 
Root cuttings should be planted shallow, usually not more 
than one-half to three-fourths inch deep, in order that the 
developing bud may soon reach the light; otherwise, as in 
too-deeply-planted seeds, the reserve food may be exhausted, 
causing death of the bud. When planted in the open ground 
(372), the soil should be made very fine, and carefully 
pressed about the cuttings; if the weather is warm and dry, 
shading (Fig. 63, p. 135) and watering will be necessary. 
b — Propagation by Cuttings from Active plants (green cut- 
ings, slips). 
377. Nearly All Plants may be Propagated from 
Green Cuttings. A succulent cutting of nasturtium 
(tropeolum), with its leaves intact, placed with its proximal 
end immersed in fresh, well or spring water, will, for a con- 
siderable time, absorb sufficient of the liquid to make good 
the loss from transpiration (75). So long as the water 
remains fresh, and the tissues of the stem are unobstructed, 
the water thus absorbed will answer the same purpose to 
this cutting as if it had been absorbed by the roots. 
Assimilation (49) will continue, and the growth current (80) 
will transport the assimilated food from the leaves into the 
stem and in the direction of the roots. No roots being 
present, however, the growing points of roots will form at 
the base of the stem, and we shall soon have a rooted cut- 
ting. Not all plants, however, can root freely in water, 
possibly owing to an instfficient supply of oxygen therein. 
