200 MAIZE 



CHAP, but it is doubtful whether any commercial maize crop grown 

 v ' breeds entirely true in regard to row numbers. That this is 

 traceable, in part at least, to fluctuating variability, seems to be 

 indicated by the following cases of irregularity : — 



Not infrequently ears are met with in which two or four 

 rows cease before reaching the tip (Fig. 83 B). 



That such cases may be dependent on nutrition, as affected 

 by variation in the character of the season, is suggested by 

 the fact that in the season 1910-11 the writer found ears 

 bearing two more rows on the upper (tip) portion of the ear 

 than on the lower portion ; the weather was dry during the 

 early part of the season, which tended to check development, 

 but was wet during the latter part of the season. The possible 

 connection between the season and such cases requires further 

 investigation before we can definitely connect them as cause 

 and effect. 



In some cases, as shown in Fig. 84B, it is clear that a 

 pair of rows has been dropped ; this is unusual, however. 

 More frequently one row of each of two pairs has stopped 

 (Fig. 831;). 



Many cases have come under the writer's notice, in which 

 two ears borne on the same plant produce different row 

 numbers ; in thirty-three plants of Arcadia Sugar-maize each 

 bearing two fully-matured ears on one culm, twelve plants 

 bore an equal number of rows on each ear ; fourteen plants 

 had more rows on the lower ear than on the upper ; on seven 

 plants the largest number was borne on the upper ear ; in 

 most of these cases there were but two extra rows, but in a 

 single case there were four more. The actual results obtained 

 are shown in Table XL. 



