Q':> 



GodlewsRi (s) found that a sudden in increase or de- 

 crease in htiraidity produced a corresponding change in 

 growth which, ho^rever, v^-as only transitory. At the end 

 of one-half hour it returned to its former rate. This led 

 him to the conclusion that the action of himidity '^as not 

 to change growth but to produce a change of turgesoence and 

 consequently turger^-distension, 



Schlosing (11), worTclng with tohacco plants, found 

 that transpiration was greatly decreased by a moist atmos- 

 phere while the gain in dry substance was increased, the 

 plants in the moist atmosphere gaining 5.2 grams per liter 

 of water evaporated as against 1.2 grams in the dry atmos- 

 phere. The composition of dry matter was also found to 

 vary under the different conditions of humidity, the per- 

 centage of ash being 13 in the moist atmosphere and 21.3 

 in the dry. In commenting upon this fact, Schlosing 

 states that all tobacco plants of any source, species or 

 degree of development, examined by him, have given in the 

 vicinity of 20;'i of ash, hence the plants grown under huiuid 

 conditions were abnormal in this respect. 



v/ollny (14) found that the dry weight and total amount 



