31 
should be even better drained than that supplied to normal 
plants. A soil made porous by the plentifial admixture 
of sand should always be selected, and in the case of 
cuttings which are being struck in pots, it is a common 
practice to insert them close against the inside of the 
porous pot, through which the air has a free access to the 
cuttings. The danger of over watering cuttings is even 
greater than in the case of well-established plants. Cut- 
tings taken from woody plants produce their wound 
tissues as well as the adventitious roots, which are formed 
later, at the expense of the food material which is stored 
in the shoot. They are not therefore so dependent on 
warmth and light in the early stages as are herbaceous 
cuttings. They. can indeed be struck in the autumn or 
winter after the leaves have fallen, or in the early spring 
before the foliage has been developed. If taken in the 
autumn they often do not produce their roots until the 
following spring, and they are always jater in the develop- 
ment of their leaves than are well-established plants. In 
the case of herbaceous cuttings which have no store of 
food material, it is necessary that they should be able to 
continue to form new organic food material in their leaves 
so as to promote the growth of callus and the development 
of roots. It is esential therefore that they should have 
pleniy of light; but in the first few days before they have 
adapted themselves to their new conditions, they are liable 
to lose too much water by evaporation, and it is important 
during this period to keep them slightly shaded, or to 
grow them in a moisture-laden atmosphere in a closed 
frame or greenhouse. It is better to prevent the loss of 
too much water by protecting the leaves in this way than 
by excessive supply of water to the soil, as herbaceous 
plants are very liable to decay by the action of bacteria 
on the cut end of the shoot. As herbaceous cuttings have 
to continue to manufacture food material, they also require 
a greater amount of heat than do woody cuttings, the 
process of leaf nutrition being stimulated by an increase 
of temperature. Herbaceous cuttings must, therefore, not 
be taken too late in the autumn unless they are to be grown 
in artificial heat. : 
A few plants can be raised from root cuttings. This 
is possible where plants are endowed by nattire with the 
power of forming adventitious buds on their roots. Rasp- 
berries, Pears and Apples are all examples of plants which 
