2IO 



BOTANICAL GAZETTE 



[SEPTEMBER 



last station yielded a very broken record during 19 10; its record 

 during 1911 has already been published (11), and at the end of that 

 year it was discontinued, as other studies upon the evaporation 

 rates in different strata were planned and in progress. 



A comparison of the records of the five stations during 191 1 will 

 be found interesting and instructive (fig, 13). Stations 16, 17, and 

 .18, upon the floor of the forest, show graphs of considerable regu- 

 larity, differing but little from each other. Their combined average 

 for the season was 7.4 cc. daily, and if this be compared with the 



Fig. 11. — Beech-maple forest; station 16; Otis, Ind 



from 



from 



of 5 . 9 cc. daily, the proportional evaporating power of the air in 

 the three strata will be found to be very nearly 1.84:100:0.80. 



from 



maxima 



minima 



daily; and seasonal averages of 8.1 cc, 7.4 cc, and 5.6 cc per 



O-I 



It is interesting here to note the close correspondence between 

 the records for this beech-maple forest and those obtained by 



