STEMS 121 



167. Bulhs. — Split an onion, hyacintli bulb, or 

 any similar structure. It will be seen tliat it is 

 simply a great bud, with the scales which surround 

 the growing point very much thickened and loaded 

 with food. The centre of the bud is a short, thick- 

 ened stem. Bulhs are buds that are usually detached 

 from the plant as soon as they are formed, and when 

 they grow, they as well as hibernacula make a new 

 individual and therefore serve to reproduce the 

 species (§ 183). 



168. Corms. — An interesting method by which 

 delicate plants endure a severe winter consists in the 

 formation of short, thick, upright stems, like those 

 of the calla or the jack-in-the-pulpit. Examples of 

 the latter may be found in almost any woods. On 

 the upper side of such short squat stems may be 

 found a large conical bud, covered by a few large 

 scales, wrapped tightly around the central mass. 

 Cut open such a bud; the young leaves and flowers 

 for the next season will be found perfectly formed, 

 except in size, as early as June or July, ten months 

 before they are to be called into action. 



169. Forcing, or inducing an earlier growth. — If 

 these corms are taken from the soil in the autumn 



