FLOWERING HORMONE MOVEMENT AND ACTION 193 



Table 10-1. Floral Stage as Influenced by the Number of 

 Buds on each Plant^ 



Number of buds examined 

 9 days after induction 



Floral Stage of terminal 

 inflorescence on shoot 

 axillary to the No. 3 leaf 

 Floral Stage of all buds 



Product of Floral Stage of 

 all buds times number of 

 buds examined 



Sixteen plants per treatment prepared 3 

 days before a single 16-hr dark period 

 (June 24, 1953) by removing all leaves but 

 the No. 3 leaf, and removing the stem tip 

 above the No. 3 leaf; buds left on the plant 

 as follows: 



Only the bud axillary to 

 the No. 3 leaf 



All buds 



64 

 6.8 

 6.1 

 392 



219 

 6.0 

 4.4 

 958 



Data previously unpublished. 



is mostly a function of concentration of flowering hormone within 

 the tissue. If this were not the case, the plants which had the large 

 number of buds should have had a much lower average Floral Stage, 

 since each bud would have had only a much smaller share of the 

 available hormone. 



Perilla is also capable of the induced state (although a number of 

 dark periods are required), and induction is quantitative and homeo- 

 static (37, 38). Yet in Perilla the induced state is extremely localized. 

 An induced leaf has been grafted to seven consecutive receptors, 

 causing each to flower, but leaves of the receptors when grafted to 

 other receptors, never caused them to flower. In Perilla the ability 

 to produce flowering stimulus is so localized that one part of a leaf 

 may be converted to the induced state, while the remainder of the 

 leaf remains non-induced. Thus if Perilla plants are induced with a 

 series of short days and then returned to long days, they will flower 

 so long as the induced leaves remain on the plant. When these finally 

 grow old and die, the plant again becomes vegetative. This appears 

 to be one neat mechanism for attaining the perennial condition. 



