COBX STRUCTURE 97 



(7) Record the total number of internodes and their average 

 length on 



(a) a tall plant and on 



(h) a low plant in the same field. 



Leaves. 



(S) {a) Record the number of leaves on an average corn plant. 



(b) In hov many vertical ranks are these arranged ? 

 (9) (a) Jvleasure the midrib of an average full-grown leaf 



and the margin of the same, to determine how 

 much longer the margin is. 

 (6) By moving the leaves about, try to ascertain how the 

 margin helps the leaves to avoid the pressure of the 

 wind. 



(c) Measure the approximate surface in square inches on 



the two surfaces of a grown corn leaf of average size. 

 {d) From (8 n) and f9 c) calculate the probable number of 

 square feet of leaf surface on 4000 com plants borne 

 on an acre. 



Ear-shanks. 



(10) in) Record the number of nodes between main stem 



and cob on a long ear-shank. 

 (5) Record the average length of five short ear-shanks 



bearing mature ears, and note whether most of the 



ears point up or down. 

 Grains. 



(11; {a) Soak grains of corn and separate tlie coats, the genn, 

 and the endosperm. 

 (h) Cut cros.-;-wise through a number of kernels of dry 

 corn and compare them as to thickness of the 

 horny layer and as to size of germ. 



LlTER.\TURE 



Sakoent, F. L. Corn Plants. Boston. 



Harshberger, J. W. Bailey's Cyclo. Agr., Vol. II, pp. .398-402. 

 Hunt, T. F. Cereals in America. Xew York. 1904. 

 Hopkins, C. G. 111. Expr. Sta., Bui. No. 87. 



H 



