10 Wisconsin Academy of Sciences, Arts, and Letters. 



Vochting 23 also found that decapitating herbaceous plants re- 

 sulted in the cessation of radial growth of the stele though in- 

 crease in diameter may result from the growth of the pith and 

 cortical parenchyma. After such decapitated plants were 

 budded cambial activity was resumed. 



Reiche 24 also notes regarding trees of Chili that radial growth 

 begins after the buds burst and that it does not occur unless bud 

 development precedes it. 



The more detailed experiments by Lutz 25 also give support 

 to Jost's conclusions regarding the relation of growing leaves or 

 buds to radial growth, and they show besides that other things 

 being equal the distribution of food may also be a determining 

 factor in the occurrence of radial growth. All the buds and 

 leaves of six to ten-year old trees of Fagus silvatica and some of 

 Pinus silvestris five to seventeen years of age were removed at 

 intervals from spring through the summer and the amounts of 

 reserve starch and growth were determined. The buds were re- 

 moved on March 20 from a Fagus which was about a meter high. 

 Branches were examined for the distribution of starch and for 

 radial growth on June 15, July 1, 15 and 30, August 10 and 20, 

 on the 10th of September, October and November, as well as De- 

 cember 5 and 23. The adventitious buds were removed but con- 

 tinued to reappear, some large ones being removed on October 

 10. Only minor fluctuations in the starch content of the pith 

 rays, wood and bark of the branches were noted through the sum- 

 mer with an almost entire disappearance of starch in December. 

 The branches remained healthy-looking but no radial growth re- 

 sulted. Similar trees were defoliated on May 20, June 15, 

 July 1, 15 and 30, and August 28 respectively, and also freed of 

 buds at intervals during the remainder of the growing season. 

 Branches of these trees were also examined on the above dates. 

 In the tree defoliated on May 20 no starch was found in the 

 branches aside from traces which occurred in the pith and 

 broad rays during midsummer, and even that had disappeared 

 by August 20. Only a small amount of radial growth took place 

 which had all occurred by July. On October 30 the stem or 

 trunk was found to contain considerable starch at the ground or 



" Reiche, K. Zur Kentniss der Lebensthatigkeit einiger chilenischen 

 Holzgewachse. Jahrb. Wiss. Bot. 30:81-115. 1897. 



16 Lutz, K. G. Beitrage zur Physiologie der Holzgewacb.se. Beit- 

 rage Wiss. Bot. 1:1-8. 1897. 



