THE METHOD OF MOVEMENT 223 



growth-controlling hormones, or both foods and hormones. 

 The appearance of the stem and the fact that the axillary 

 shoots stopped growing when the part above recovered 

 demonstrated that the parts were not killed. 



Child (1921) and Child and Bellamy (1919) found that 

 local chilling of the stem of the scarlet runner or lima bean 

 would induce the formation of shoots below the chilled 

 portion. Similar local chilling of the runner of Saxifraga 

 sarmentosa, they found, would induce the development 

 of a plant at the runner tip. These regeneration effects 

 are similar to those induced by ringing or by local killing 

 or anesthesia of the stems. The writers concluded that 

 there could have been no interference with movement of 

 materials since the shoots did not wither and the growth 

 of the runner tip seemed normal. Therefore they explained 

 the effect of chilling as due to an interference in the trans- 

 mission of an influence or stimulus comparable to an 

 effect of local chilling on the transmission of a nerve 

 stimulus. Although these regeneration phenomena are 

 induced by cutting, killing, anesthesia, or chiUing of the 

 phloem tissues and may therefore be due to an interrup- 

 tion of solute movement, one is not justified in concluding 

 from this that interfering with solute movement alone will 

 fully account for regeneration. The same phloem tissue 

 may take part in both transportive and transmissive 

 effects. The fact that the phloem contains living cells 

 with well-developed protoplasmic connections might be 

 considered to favor both the transmissive and transportive 

 explanations. 



More recently it has been demonstrated (Curtis, 1929) 

 that similar local chilling actually does interfere with the 

 backward transport of carbohydrate from the leaf blades. 

 Details as to procedures and results can be found in the 

 original paper. The data presented in Table 24 represent 

 the type of results obtained. It is clear that backward 

 transport is checked or stopped when a part of the petiole 

 or stem is chilled to a temperature somewhere between 

 and about 6"C. Later investigations indicate that it may 



