A Study of Evaporation and Plant Distribution. 217 



alteration in the vegetation, it taking almost the same form here 

 as that of the northeastern conifer center. With the return to 

 an average weekly rate of about 100 cc. tlic vegetation is 

 again deciduous forest. 



Tlie lower profile, Fig. 1 , is drawn across the northern limits 

 of the United vStates and passes into Canada. It extends fiom 

 Seattle to Frederictcn, X. R., through Legina, Houghton, and 

 Quebec. The station for the latter j^lace was MacDonald 

 College, vSt. Annes. Although data for an indication of the limits 

 of the different vegetational types along this entire profile are 

 not at hand, it is clear that the highest evaporation intensities 

 accompany the grassland vegetation (this profile does not 

 traverse true desert) and that the lowest occur with either the 

 nortliwestern or northeastern conifers. 



CoNtrcR-DcctD- t'"'T"''i"''H Swamps amb Mafbhis. llilll^'^'-^*li^|lM 

 Otheti Types as on FonEQOiNt Protilis. 



Heci 



Camion 



Figure 2 



The up er profile of Fig. 2, passes fiom Fredericton,N.B., to 

 Miami, through Orcno, Ivaston, Raleigh and Gainesville. The most 

 striking feature of the diagram is its evidence that the highest 

 summer e^•aporaticn intensities occur with • the southeastern 

 conifers or with the Florida marshes. 



The lower diagram, Fig. 2,is a profile from Regina,Sask,to Cam- 

 eron, La., passing thiough Dickinson, North Platte, and Stillwater. 

 The highest atmo metric rates, in the north, accomjany grass- 

 land, being about 150 to 280 cubic centimeters, or above. The 

 lowest rates, in middle latitudes, represent roughly the decid- 

 uous forest or prairie vegetation; and the somewhat higher 

 rates, at the south occur with the southeastern conifers. 



It is hardly necessary to disavow here any attempt at 

 detailed accuracy in connection with these profiles; neither 



