BOTANICAL CHARACTERISTICS, 15 
to the next. In a study of the corn plant at 
the lowa experiment station,* the number of 
leaves on a stalk varied with field corn from 12 
to 18, with a width of blade from 5% to δὲ in- 
ches. Microscopical examination of a number 
of varieties showed considerable difference in 
the thickness of the leaf structure and in the 
amount of green coloring matter present. At 
the Missouri station, Prof. Schweitzer measured 
the leaf surface of a vigorous plant of average 
development. “The total surface of the twelve 
living leaves on one side was 1,655.73 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 18 may be produced in our climate, the lower 
ones die off 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, 
* Towa agricultural college experiment station. Bulletin 
No. 2, September, 1888. 
+ Missouri agricultural experiment station. Bulletin No. 
5, February, 1889. 
