BOTANICAL CHARACTERISTICS. 15 



to the next. In a study of the corn plant at 

 the Iowa . experiment station,* the number of 

 leaves on a stalk varied with field corn from 12 

 to 18, with a width of blade from 3f to 5 J in- 

 ches. Microscopical examination of a number 

 of varieties showed considerable differenco in 

 the thickness of the lesif structure and in the 

 amount of green coloring matter present. At 

 the Missouri station, Prof. Schweitzer measured 

 the leaf surface o^ a vigorous plant of average 

 developmentif "The total surface of the twelve 

 living leaves on one si(Je was 1,633.73 square 

 inches, which doubled for both sides, and add- 

 ing the area of the outside of the sheaths, 

 makes the total external leaf surface of this 

 plant 3,480 square inches, or 24 square feet." 

 Schweitzer considers the leaves the chief source 

 of production of organic matter, and while 16 

 or IS.may be produced in our climate, the lower 

 ones .die ofE before maturity, and activity is 

 confined to perhaps twelve. 



The flower is of two kinds, male and female/< 

 The former is known as the tassel, and is situ- 

 ated at the tip of the stem in the form of a 

 branching head (panicle), while the latter is lo- 

 cated in between the sheaths of leaf and stem. 



* Iowa agricultural college experiment station. Bulletin 

 No. 2, September, 1888. 



t Missouri agricultural experiment station. Billletin No; 

 5, February, 1889. 



