226 BOTANICAL GAZETTE [apml 



Quercus alba, Nyssa sylvatica, Liriodendron tulipif^ 



nus americana, 

 virginianaj Vil 



Hamamelis 



alnijolia 



indi folia 



lisma ligiistrinn. The herbaceous layer contains Osmunda cinnamo- 

 mea,Spalhyaema joetida^ Viola cuciillata, Trillium cernuum,Dryopteris 

 noveboracensisj Arisaema iriphyllum, Carex crinita^ C. Asa-Grayt, 

 Veratiim viride, etc. 



June 10-19 June 19-24 June 24-28 Total (18 daj-s) 



Amt. evaporation, Station 8 20.2^^ 11.3^^ 9.5"^'' 41 -o" 



Amt. evaporation 



112. 6 94.7 4^4-6 



or_ 



Comparative evaporation . , 9 . 7% 10 . 0% 10 . 0% 9-9/0 



This record seemed very surprising at first, but as the records from 

 the other habitats increased, it proved to be entirely in harmony with 

 them. During the preceding summer I took some comparative tem- 

 perature and relative humidit} 



gie garden. Though the temperatures ran somewhat lower and the 



relative humidity higher, one would scarcely have predicted an evapo- 

 ration difference of 90 per cent, for the lower stratum of the two 

 stations. The failure to take into accoimt the relative air movements 

 in the two situations is the probable cause of the apparent discrepancy; 

 but the comparison helps to emphasize the importance and efficiency 

 of the porous-cup vaporimeter as a means of differentiating habitats. 

 Station p.— Upper beach area, on " East Beach," 3^ north of 

 Northport; altitude 4^. This area is generally considered, on the 

 basis of the vegetation, the most xerophytic along the Sound in the 

 Aicinit}^ of Cold Spring Harbor. The direct distance from the 

 Carnegie garden is i2^°». The vegetation is dominated by Am- 



mophila arundinacea, Rosa humilis, Paniciim amnrumj Lechea man- 

 iima, Artemisia caudata, Chrysopsis jakata, Polygonella articidata, 

 Solidago sempervirem, Hudsonia tomentosa, and Opuntia optintia. 

 The vaporimeter was placed among some shoots of Rosa kumihs, 

 Just sufficiently screened so as not to attract attention. The coarse 

 sandy substratum slopes gradually to the south at this point. 



June 27- July 19 

 (22 days) 



Amt. evaporation. Station 9. 332 . i^^ 



Amt^ evaporation, standard 424-3 



Comparative evaporation 78 . 2% 



