64 



■ ;ga ' luoe-iB.- - t h^ maximum by a corresponding increase of growth. 

 For C!hewsville» as an example, in the period beginning Aug. 11 

 we have a low value for the leaf-product with a high tempera- 

 ture index and the other conditions at about the seasonal av- 

 erage. For Monrovia in the period beginning Aug. 10 with 

 high temperature value and sunshine at about the seasonal av- 

 erage the plants show, nevertheless, a relatively low v ,lue 

 of the leaf-product. This may be contrasted with the period 

 beginning June 15 at this station which, with a leaf-product 

 about the s^me as that of the firs^'-m'^ntionei period shows 

 less favorable growing conditions, namely, a much lower rela- 

 tive temperature index, a very high evaporation rate and a sun- 

 shine value only a little higher than the corresponding value 

 of the period beginning Au^. 10. For College, the oeriods 

 beginning July 17, July 31 and Aug. 14 with about the same 

 values of temperature and evaporation show magnitudes of 152, 

 203 and 150, respectively, for the leaf -product. This varia- 

 tion may oossibly be related to differences in the value of 

 sunshine intensity for these periods, but the sunshine data 

 are lacking for this station. For Baltim:re, the periods 

 beginning July 23, Au-j. 6 and Aug. 20 show large variations in 

 the leaf-product with comparatively slight variations in the 

 climatic conditions. Evaporation is slightly less in the per- 

 iod beginning July 23 than in the period beginning Aug. 6 

 and considerably less in the period beginming Aug. 20, but this 

 seems to be without the expected effect on the r)lants. For 

 Ocleman the plant graph siopes upw.rd to a value o-^ ovr 200 

 for the period begirjiing July 8 vrhile for the oericd beginning 

 Aug. 5, which has climatic corditior.s apparently as favorable, 



