ORIGIN AND CLASSIFICATION 



21 



Fig. 6. — Pop corn. 



supposed by some persons that pod corn represented 

 a primitive or early type of corn, but there is no good 

 evidence for this surmise. 



3. Zea Mays everta, the pop corns. 

 Characterized by the excessive proportion of corneous 

 endosperm and the small size of the kernels and ear. The 

 popping quality is due to the explosion 

 of contained moisture on the applica- 

 tion of heat, and the best varieties 

 for popping are usually corneous 

 throughout. Two forms of seed are 

 common, one of which is pointed at 

 the top (rice pop corn), and the other 

 form is rounded (pearl pop corn), 

 much as a small flint. All maize 

 colors are found, as red, yellow, white, 

 and blue. The ears are small but vary in length from 

 2 inches in Tom Thimab to 5 inches for rice and 7 inches 



for some of the large pearl 

 types. Rows vary from 

 8 to 16. 



4. Zea Mays indurata, the 

 flint corns. 



Characterized by white 

 starchy endosperm, inclosed 

 by flinty endosperrh. Ker- 

 nels oval in form ; in some 

 varieties the corneous part is very thin at the top and a 

 slight indentation appears. There are types of flint 

 maize closely resembling pop corn on the one hand and 

 approaching dent on the other, thus forming a series 

 between the pop and dent corns. Flint maize has all the 

 common maize colors. It varies in length of ear from 8 to 



Fig 7. — Flint corn. 



