152 



MAIZE 



CHAP. 

 V. 



depth (f 1 06) with the shape which allows the least waste of 

 space between rows, is obviously the one that will give the best 

 yield, other things being equal. The ideal shape for this pur- 

 pose is known as the wedge-shape (cf. Fig. 68 and IT 108). 



1 10. Effect of Number of Rows. — It does not always follow 

 that increase in number of rows of grain on the ear is accom- 



A B 



Fig. 67. — Result of breeding for reduction of sulci ; Doyle Hickory. 



panied by increase in amount of grain produced. Cases illus- 

 trating this point have been mentioned in chapter IV. (1" 85). 



One number of rows usually predominates in a breed, thus 

 in Iowa Silver-mine it is the 16-row, of which there were 57 per 

 cent, while of the 14-row there were only 24 per cent in 

 certain cases examined. It does not follow, however, that the 



