Moisture and Fruit-growing. 9 



degrees of latitude (reaching northwards to about 

 27). Beyond all these bounds there are special 

 localities in which fruits of the adjacent zone may 

 thrive for a series of years, and the fruits of con- 

 tiguous zones overpass. The strawberry is probably 

 the most tractable of all our fruits as respect 

 climates, because its stature and habit allow it to be 

 protected from extreme cold and its short period 

 of growth allows it to thrive in the cool season 

 of the warmest sub -tropical regions. 



The annual temperature of a region is chiefly 

 determined by three factors, the latitude, the 

 altitude, and the proximity or remoteness of large 

 bodies of water. 



The moisture determinant. The second chief fac- 

 tor of climate in determining the fruit -zones is rela- 

 tive humidity. Whilst the isotherms or lines of 

 equal temperatures run easterly and westerly, the 

 isohyetals or lines of equal rainfall have no in- 

 trinsic direction. They are determined by physio- 

 graphical characters. In the United States, there are 

 three general fruit-zones which are marked by pecu- 

 liarities of rainfall. These are the Atlantic zone, 

 a moist area which is bounded westward approxi- 

 mately by the Mississippi River ; the plain zone, 

 extending westward to the mountains ; and the 

 Pacific slope zone. The two latter are relatively 

 dry.* The interior or plains region is particularly 



*We should, perhaps, make a fourth division, to comprise the arid or 

 Sonoran zone of New Mexico and Arizona, but this area is yet too little 

 known in a pomological way to demand specific treatment here. 



