The Orchard Plant 65 



transport the food after it has been transformed into prod- 

 ucts which plants may use. 



Starch is formed only during the daytime, and it is 

 reasonable to suppose that the greater amount of sun- 

 shine common to the arid regions must result in a larger 

 production of starch. This must be one important reason 

 why plants are more fruitful in the higher altitudes. 

 Other and more complex materials are produced at night 

 by the combination of the starch with the materials 

 brought in from the soil. The uniformly cool nights may 

 hinder this part of plant-food manufacture, and thus tend 

 to retard growth, resulting in early bearing and fruitful- 

 ness. 



