154 PROPAGATION OP PLANTS. 



entirely excluded from the light, or wholly buried in the 

 soil; for in making them, the leaves are left on that 

 part of the cutting which remains above ground when 

 planted. If covered entirely, as we do with decidu- 

 ous cuttings, they would soon decay. The leaves of 

 our hardy evergi-een coniferous plants are covered 

 with a compact epidermis, which does not permit 

 them to either absorb or exhale moisture very rapidly 

 when in a dormant state, and this peculiarity in struc- 

 ture admits of their being placed in such a position that 

 roots will form while their leaves do not sufEer. In cold 

 climates they should be placed in what are termed cold 

 frames, and covered with glass that has been dimmed 

 with some kind of a wash that will prevent the direct 

 rays of the sun reaching them, and still admit sufficient 

 light to keep them in health. In the coldest weather the 

 frames may be covered with straw mats to keep out the 

 cold and prevent severe freezing. The Arbor-vitaes, 

 Evergreen Box, Yews and Junipers, are quite readily 

 propagated from cuttings made of tlie dormant wood in 

 the fall, although this mode of propagating these trees is 

 seldom practised, probably because there are others less 

 hazardous, and perhaps more convenient. 



CHAPTER XII. 



BY CUTTINGS OF IMMATTJKE GROWTHS. 



When propagating by cuttings of the young, growing 

 wood, or succulent parts of herbaceous plants; ^we are 

 operating with an active vegetation instead of one -that is ■ 

 dormant. In the cuttings made from ripe wood, there 

 is a supply of organized material from which roots are 

 produced ; but in those made from the young and grow- 

 ing parts of plants, this is only in a state of transmutation^ 



