30 



Journal of Agricultural Research 



Vol. XIX, No. I 



The significant coherences with characters in the alicole group aflford 

 perhaps the most direct evidence that has appeared that the characters 

 of the pistillate inflorescence tend to be inherited as a unit. 



The correlation with rows in the central spike is perhaps physiological. 

 There are no significant disherences. 



NUMBER or' SUCKERS 



Florida teosinte is characterized by a large number of suckers or 

 branches that arise from below or near the ground. In a population of 

 Florida teosinte at Chula Vista, grown in 191 7, the average number of 

 suckers was 14. Tom Thumb never produces suckers on normal plants, 

 and no variety of maize has been studied that produces as many suckers 

 as teosinte. The expression of this character is so dependent on environ- 

 mental conditions, however, that statements regarding the range in 

 maize would have little value. The most vigorous F^ plant produced 

 II suckers. 



In the second generation the range was from o to 32, with the mode at 

 13 and the mean at 11.7. There is no evidence of more than one mode 

 (fig. 29). 



There are, in all, three significant correlations with this character, nodes 

 without branches, single female alicoles, and double female alicoles — 



all of them coherences. The first of these is 

 obviously physiological, since a large number of 

 suckers and a small number of vacant nodes are 

 both expressions of a tendency to produce 

 branches. The other two are practically Affer- 

 ent expressions of the same character and indi- 

 cate a coherence. 



BRANCH SILKING FIRST 



^'O 







In recording this character the primary 

 branches were counted from the top. In maize 

 the uppermost branch is the first to silk, except 

 Fig. 29.— Number of suckers: fre- \^ j-^re instances where the second ear may silk 



quency distribution of plants in , , . , e ^^ c ^ t ^ • ±. 



F2. Class value, two suckers, a day or two lu advancc of the iirst. in teosmte 

 One plant at 32. ^-jjg fourth or fifth branch is usually the first to 



silk. This character therefore distinguishes sharply between the parents 

 with respect to both the variety and the species. 



The F2 hybrid plants ranged from i to 5, with equal numbers at i and 2 . 

 The mean was 1.9, the distribution (fig. 30) was skew and unimodal. 



With the height group there are two significant correlations, one a coher- 

 ence with total leaves, the other a disherence with sucker index. This 

 disherence doubtless results from the negative correlation between total 

 leaves and sucker index. The partial correlation of node silking first 



