94 



Otis F. Curtis 



that treatments which would affect the rest period might not also have 

 an effect on root growth. In order to test this point, Ligustrum twigs 

 were taken on November 13 and tied in bundles of twenty twigs each. 

 These bundles were suspended in water for two hours, at the depths 

 and temperatures indicated in table 6, and were then placed in sand in 

 the cutting bench. It is to be noted that at each temperature the top 



TABLE 6. Effect of Warm-Bath Treatment on Dormancy and Root Growth 



(Treatment lasuing two hours; (a), from 2s to 3 centimeters at base immersed; (c), entire 

 twig immersed. Twenty twigs per culture) 



Treatment 



Total root 



length 

 per twig 

 (milli- 

 meters) 



Order of 

 greatest 



root 

 growth 



Total top 

 length 



per twig 



(miUi- 



meters) 



Order 



of 



greatest 



top 

 growth 



1 (a) Check 20° C 



1 (c) Check 20° C 



2 (a) 35° C 



2 (c) 35° C 



3 (a) 40° C 



3 (c) 40°C 



4 (a) 45° C 



4 (c) 45° C 



10± 3.8 



6± 3.4 



38± 8.9 



20± 6.1 



55±10.8 



35d= 7.6 



2± 0.4 







6±2.3 



4±1.6 

 23±3.8 

 20db3.4 

 29±4.1 

 28±4.6 



3±1.1 







growth, as well as the root growth, was better in those twigs of which the 

 bases only were immersed. The order of greatest growth of roots follows 

 almost identically that of the greatest growth of tops. The results indicate 

 that some treatments which start or increase growth in the entire twig 

 may correspondingly increase root growth. It does not seem possible, 

 however, to start growth at the base of the twig by the warm-bath treat- 

 ment and leave the tops dormant. 



Very similar results as to root growth were obtained with twigs taken 

 on September 10 and treated in the same manner. No notes as to the 

 effect on top growth, however, were made at that time. 



Effect of treatment on correlation between tops and roots 

 Another possibility that has suggested itself is that the treatment 

 may have brought about a change in correlation between tops and roots, 

 an effect that might be due to a divergence of food movement from tops 



