GROWTH. 8 1 



EXPERIMENT 108. 



ACCELERATED DEVELOPMENT OF SHOOTS. 



Cut off twigs of Syringa (Lilac), Cornus (Dogwood), Salix 

 (Willow), etc., in several winter months ending with February, and 

 place them in water in a warm room, or, better, under a bell-jar to 

 keep them moist. The development of the buds proceeds accord- 

 ing to the laws given above. 



65. Correlation Processes. Not all the shoots of a plant come 

 to full development. Only the strongest and most useful to 

 the whole plant develop, while the others either perish or carry 

 on a kind of " sleep-life." These last are generally styled 

 latent buds. If the plant is robbed of a " concurrent " organ 

 by any accident, the nourishment heretofore used by that organ 

 is sent to a latent bud, which then emerges from its period of 

 rest and develops. Such phenomena are termed correlation 

 processes. In gardening much use is made of this capacity of 

 the plant ; as, for example, in the formation of thick hedges, 

 in the development of branches and flowers F IG> 70 . 



on the Fuchsia, etc. 



EXPERIMENT 109. 



DEVELOPMENT OF LATERAL SHOOTS OF THE BEAN. 



Germinate two plants of Bean in pots. Cut 

 the epicotyl from one as soon as it appears 

 above the ground. Then the buds in the axils 

 of the cotyledons develop instead. The otherj 

 plant serves as a means of comparison. 



EXPERIMENT no. 



DEVELOPMENT OF LATERAL BUDS OF THE POTATO. 



Place a Potato-tuber with the stem-scar 

 underneath in a warm room without the addi- 

 tion of water. The buds near the top develop. 

 Cut these off and the lower ones start into Sprouting Potato, 

 active growth. (Fig. 70.) (Detmer.) 



66. External Mechanical Force Exerted by Growing Organs. 

 The growing cells of plants are able to exert a pressure on 



