6 4 



Richard H. Boerker 



the xerophilous species the highest per cents, are in the loam and 

 sand, among the xero-mesophilous species the highest per cents, 

 are in the sand while in the mesophilous species the highest per 

 cents, are in the sand and loam. Out of 34 species, 18.5 ger- 

 minated highest in the sand, thus showing the value of this class 

 of soil for seed germination. 



TABLE XV 



Summary of the Final Germination Per Cent, by Number of Species. 



Light 



Number of Species 



Soil Moisture 



THE EFFECT OF HABITAT FACTORS UPON STEM AND ROOT 

 DEVELOPMENT 



Following the experiments upon germination, some of the 

 species were grown for several months for the purpose of ob- 

 taining root and stem measurements. Since damping-off re- 

 duced materially the number of seedlings as time went on, the 

 number of plants upon which final measurements could be taken 

 was naturally reduced. Hence the results are not based upon as 

 many measurements as was originally intended. 



