92 



Harshberger. — Maize , 



dry weather than the ordinary varieties, which were harvested 

 a month before. The so-called wild corn possessed greater 

 constitutional vigor than the ordinary cultivated forms. 



The tables which follow, from the records of the United 

 States Signal Office in Philadelphia, may prove of value in 

 this connection. The first table shows the rainfall for the 

 month of September, 1892 : 



Rainfall, September, 1892, Philadelphia. (Inches.) 



September and October were very dry. The thermometer 

 stood for the thirty days of September above 59 F., a tem- 

 perature favorable for the plant's growth, but on only one 

 day did the rainfall exceed one-half inch. October showed 

 no days with the temperature below 32 . A comparison with 

 the October rainfall of the previous twelve years showed that 

 this was the dryest October in that whole period of years ; 

 0.30 inch of rain fell. The thermometer did not vary so 

 greatly ; the mean of the whole month was 56.4 F. 



November was also dry until the fifteenth, when two 

 inches of rain fell. The greatest precipitation during the first 

 fourteen days occurred on the ninth and tenth days, when 

 .52 and .86 inch fell respectively. These figures show the 

 power that the possible wild species had of thriving well with 

 little rain, and are valuable as showing the conditions favor- 

 able to the growth of the plant in its Mexican home. Data 

 collected by the Mexican Observatory from numerous sta- 

 tions in central Mexico are compared with the Philadelphia 

 temperature and rainfall, as showing the localities in Mexico 

 meteorologically suited to the wild plant's growth. 



The following table, compiled from the Boletin Mensual, 1 



1 Boletin Mensual Observatorio Meteorol6gico-Magnetico Central de Mexico, Resu. 

 men del Afio, 1889, 37. 



