352 Schively — Contributions to the Life History of 



conditions. Possibly the above statement may apply even 

 in the case of the purple flower ; and experiments are now 

 in progress to test the matter. 



The abundance of axillary shoots, both primary and 

 secondary, presents a feature quite different from the plants 

 just discussed, as does also the habit of growth. The 

 cotyledonary, axillary shoots normally produce many flowers 

 and fruits. The runners above ground may do so likewise, 

 and if a darkened moist place is reached, the ovate one- 

 seeded legume results ; otherwise a flat green legume 

 resembling a diminutive aerial type is produced. These 

 runners are not provided with any device to assist them in 

 forcing their way into the soil. The runners from the 

 simple leaves are not strongly geotropic ; perhaps after a 

 certain period of growth, they are best described as nega- 

 tively heliotropic, yet the secondary branches frequently 

 exhibit beautiful geotropic curves.- The axillary runners 

 from compound leaves are negatively geotropic, yet these 

 may be so treated that subterranean flowers and fruits are 

 borne. The cotyledonary axillary runners are feebly geo- 

 tropic, extending from the cotyledons at an angle of 75 to 

 90 degrees. 



In Arachis and Trifolium the geotropic characteristics of 

 those portions bearing the flowers which are capable of ma- 

 turing underground, are quite pronounced. 



The purple flowers of Amphicarpcea evidently require 

 for their development, as has already been stated, consider- 

 able light intensity, and possibly also demand the vigorous 

 growth of the upper portion of the plant. When the spe- 

 cial period for the production of these is past, the aerial 

 apetalous form appears. The seeds in these legumes are 

 numerous, yet they possess a very hard covering, and are 

 difficult of germination. Filing these produced such a 

 marked difference in percentage records of germination 

 that the success obtained by similar treatment of Trifolium 

 seeds matured above ground is recalled. 



The subterranean fruit of Amphicarpcea is larger, and 



