56 



Plant Physiology 



able for most cultivated plants. This may be reduced to 

 less than 1 per cent in coarse sand, and may rise to more 

 than 50 per cent in typical New York muck. The tables 

 which follow are after Heinrich * ; the first shows the rela- 

 tion existing between water capacity, hygroscopic water, 

 and unavailable water ; . the latter table gives a suggestion 

 as to the conduct of different crops on two types of soils : 



PLANT 



MOISTURE CONTENT AT WHICH PLANTS 

 BEGIN TO WILT 



1 Cited by Cameron and Gallagher, Bureau of Soils, U. S. Dept. AgL 

 Bui. , 50 : pp. 57-58. 



