1914] 



OTIS— TRANSPIRATION OF WATER PLANTS 



459 



among them 



come to the same 



may 



stems 



ing plants were used. It is to be noted, however, that, during the 

 period of the experiment, the amount of water absorbed and the 





TABLE I 









Absorption 



Transpiration 



cc. 



0:1=; A.M. -6 : 2 S P.M 



11.30 



8.05 

 11.30 



7.67 



12. 80 



6.48 

 II.80 



5-21 



+1.5 



-i-57 



+0.5 

 • -2.46 



O: SO A.M.-7-.OS P.M 



7*.Os P.M.-7I2S A.M 





amount transpired were not greatly different, being 3.8.32 cc. in the 

 one and 36.29 cc. in the other, showing a difference of 2.03 cc. for 

 42 hours. Eberdt's results with Helianthus annum, as reported 

 by Burgerstein, show even a smaller difference, his figures for a 



period of 24 hours being as given in table II. 



TABLE II 



Time 



Evaporation of 

 water in cc. 



Absorption of 

 waier in gm. 



7:15 P.M.- 8:45 A.M 



3:00 P.M.- 7:15 P.M 



16.67 



4-95 

 5-5° 

 6-45 



1555 



5-53 

 7.40 



5-5o 



7:15 P.M.- 7:15 P.M 



33-57 



33 98 



Eberdt's results, employing the potometer method, are not 

 entirely satisfactory for the reasons stated above. Summarizing 



BURGERSTEI 



experiments 



using plants 



normal 



approximate 



there may be assumed a certa 

 intake and water outgo. 



Vesque (ii), experimenting 



between water 



subjected to 



comes to the conclusions ( 



