34 Journal of Agricultural Research voi. xix, no. i 



four correlated characters constant was found to be — 0.69. Such rela- 

 tions must stand, therefore, as disherences so far as the recorded data 

 are concerned. 



A study of the correlations shows that wilhin wide physiological 

 limits there are no incompatible combinations. On the other hand, 

 all the characters are in a sense interrelated. Having in mind the theory 

 that ascribes the determinants of characters to definite locations on the 

 chromosomes, the authors examined the correlations to determine whether 

 there were groups of characters between which there were no significant 

 correlations. No such grouping was apparent, and it was possible to 

 arrange the entire series so that they formed a single group with no corre- 

 lation lower than ±0.31. 



If the results of this experiment are interpreted in terms of the theory 

 mentioned above, it follows from the blended character of the inheritance 

 that practically all the characters result from the combined action of 

 numerous factors. The failure of the characters to fall into groups the 

 members of which are genetically correlated further indicates that the 

 factors for the individual characters must be distributed in different 

 chromosomes. 



CORRELATION AMONG DESIRABLE CHARACTERS 



Among the characters measured, a certain few are indicative of desir- 

 able characteristics from the standpoint of a forage plant. The more 

 important of those are (i) total leaves, indicative of the luxuriant 

 foliage of the teosinte, (2) circumference index, a small circumfer- 

 ence in proportion to the height indicating the slender, edible stalks 

 of the teosinte, (3) nodes silking on third branch, indicating the pro- 

 fuse production of seed of the teosinte, (4) number of suckers, indicat- 

 ing the abundant production of forage of the teosinte, (5) male branch 

 index, indicative of the numerous branches of teosinte, (6) number of 

 alicoles in the best spike, indicating the large pistillate inflorescences of 

 maize, (7) rows in the central spike, indicating the many-rowed inflo- 

 rescences of maize, and (8) days to pollen, a low value indicating the 

 short season of maize. 



The interrelation of these selected characters is shown in Table VI. 

 Of the 27 combinations of these characters there are 9 in which both of 

 the desired characters are possessed by teosinte, 3 in which both are 

 possessed by maize, and 15 where it is desired to combine teosinte and 

 maize characters. 



