190 Principles of Plant Culture. 



354. The Corm (Fig. 92) differs from the bulb chiefly 

 in being without scales. The food is deposited in the 



thickened stem. The 

 conns of onr flowering 

 plants, as the croc us. cyc- 

 lamen etc., are general- 

 ly called bnlbs in com- 

 merce. 



355. The Tuber,of which 

 FIG. 91. Buibiets FIG. 92. Corm of the common potato is the 



of "top" onion, crocus with small mogt famiUaj . example, 



sometimes used as corms (buds) for fol- 



onion " sets." lowing year. differs from the COrni ill 



being the end of an underground branch of the stem 

 (115), instead of developing in direct contact with the 

 parent. It also has more numerous buds (eyes) than the 

 corni. * 



356. Propagation from Bulbs, BulbIets,Corms and Tubers 

 is a very simple operation and consists merely in plant- 

 ing these parts in the place where the plants are desired. 

 Tubers may be cut into pieces containing one or more 

 buds each, if desired. The rules given for planting seeds 

 (344) apply equally well here. All should be stored for 

 preservation in a cool, moderately dry place, that is free 

 from frost. They retain their vitality but a single 

 year. 



In the methods of propagation thus far considered, 

 with the sole exception of layering (349), advantage has 

 been taken of a natural mode of plant multiplication. 

 The skill of the cultivator, however much it may assist 

 the processes, is not necessary to their success, since wild 

 plants habitually increase by the same methods. We 

 will now consider a method which is less often illustrated 



