VEGE TA TIVE REPJ^OD UCTION. 



267 



Some species o\ Khinia, natives of Cajje Colony, ha\'e flesliy 

 stems, jointed at iiiter\als, so that they easily Vjreak there. 

 When broken off by an accident, the piece rolls away, takes 

 root from the under side, and sends up shoots from the upper. 



Ad\antage is taken of this power of se\"ered parts to form 

 adventitious roots and shoots in the artificial pro]iagation of 

 domestic jilants. Suitable portions of shoots or leaves for 

 the development of new plants under proper conditions are 

 called cuttings, scions, or "buds." They may generally be 

 grown in water or soil ; or they niav be securely fastened in 

 a slit or wound in another jijant. The latter process is 

 known as grafting or budding, according to the form of the 

 impjlanted part. Indeed brood buds in general ma}' be 

 looked upon as natural cuttings or scions. 



368. Brandling. — A further modification of this method 

 of reproduction is to be ob- 

 served in the formation of 

 new individuals through pjro- 

 gressive death of the old 

 parts. If a plant, dying thus, 

 be a branching one, death will 

 sever the branches as it reaches 

 them S0(jner or later, and 

 each Ijrani h tlien becomes an 

 independent plant. Tliis is 

 seen in its simplest form in 

 those |;lants which have a hori- 

 zontal branching tliallus whose _p 

 base dies as the apex elongates Fig. 300.— Outline of a tiiailus of .!/«>•- 



chantia ^eminai'i. Tlie base l> is 

 (fig ^00). It is common in dj-ing as tlie apices are growing and 

 ^ ° "^ branctiing. When deatfi reacties ttie 



plants with undergroimd creell- first for]<' there mil be two independent 

 ^ _ . plants ; at tlie second there will be four, 



ing stems which send u|) aerial and so on. 



leaves or shoots annual!)', as do the ferns of temperate regions 



and many grasses and mints. 



