178 Principles of Plant Culture. 
favoring the formation of the organs needed to make it self- 
supporting; or if a cion, favoring its union with the stock 
(383). 
a. Propagation by Parts Intact. 
This method is applicable to many plants, and has the 
advantages of being reliable and requiring little skill. The 
part selected for propagation, being nourished by the parent 
until it forms the needful organs, is able to endure unfavor- 
able conditions that would prove fatal in most other meth- 
ods of propagation. This method includes four divisions, — 
viz., propagation by suckers (347), by stolons (348), by layers 
(349), and by approach grafting (399). In the first two, the 
propagation is performed by the parent plant without other 
aid than the maintenance of a well-aerated, moist and clean 
soil that stimulates the production of the needed organs, 
which in these cases are roots. 
347. Propagation by Suckers. Suckers are shoots 
that originate from roots or underground stems and grow 
upward, forming young plants about the parent, as in the 
blackberry, plum, choke-cherry etc. The propagation con- 
sists in simply cutting off the stem or root whence the 
sucker proceeds, and transplanting the latter. 
The growth of suckers may generally be stimulated, in 
plants that naturally produce them, by cutting off the roots. 
or underground stems from which they grow, or by severely 
pruning the top. 
The propagation of woody plants from suckers is not 
considered wise as a rule, since the roots are usually poorly 
’ developed in proportion to the stem, and some plants grown 
in this manner seem to acquire the tendency to form suck- 
ers excessively. In the red raspberry * and the blackberry,t 
* Rubus strigosus, R. Ideus. { R. villosus. 
’ 
