A UNIT IN AGRICULTURE 27 



PART II. 



STUDENTS' LABORATORY MANUAL. 



FARM CROPS. 

 Ex. 1. A Grain of Com. 



Soak a few grains of corn in hot water for twenty minutes. With 

 a small sharp knife, remove the tip cap. This tip cap is a small cap 

 covering the end of the kernel. Beginning at the end where the hull 

 has been broken by the removal of the tip cap, pull off the hull in 

 strips. The part immediately under the hull and covering almost or 

 quite all of the kernel is called the horny gluten. Carefully remove 

 it by shaving it off with a sharp knife. Now carefully remove the 

 germ. Notice carefully the size, position and parts of the germ. After 

 the tip cap, hull, horny gluten, and germ have been removed, there 

 remains only starch, of which there are two kinds the horny starch 

 and the white starch. The horny starch lies next to the horny gluten 

 on the back and sides of the kernel. The white starch occupies the 

 crown end of the kernel above the germ, and it also nearly surrounds 

 the germ toward the tip of the kernel. Separate, as far as possible, 

 the horny starch and the white starch. How many and what distinct 

 parts have we found? Make an enlarged drawing of grain of corn, 

 front view, showing and naming the parts. 



Ex. 2. An Ear of Corn. 



Material : three or four different varieties of corn grown in the 

 neighborhood. Table the varieties by name. Observe carefully and 

 note the following: (1) color of grain, color of cob, and whether sur- 

 face of ear is smooth, rough or very rough ; (2) number of rows, num- 

 ber of grains in a row; (3) total number of grains on the ear; (4) 

 whether the rows are straight or twisted, and, if twisted, which way; 

 (5) whether the grains arc closely packed or loose, firmly attached to 

 the cob or loosely attached; (6) whether shafpe of ear is cylindrical, 

 conical, or irregular. Do you think the ear is well proportioned? 



