450 Journal of Agricultural Research voi. vr, ko. « 



Since endosperm texture is strictly alternative, while all other charac- 

 ters were expressed in varying degrees, the method for calculating the 

 correlation coefficients was necessarily different for this group of character 

 pairs. In calculating the correlations with endosperm texture Pear- 

 son's (1909) method for calculating a biserial correlation, together with 

 Soper's (19 14) formula for the probable error, were used. With a strictly 

 alternative character such as endosperm texture, it would seem impos- 

 sible to distinguish physiological from genetic correlations. Since one 

 variety always has waxy and the other always has homy endosperm, to 

 detect correlations with this character in the parent varieties seems out 

 of the question. Likewise, as a result of the dominance of the homy 

 endosperm, the seeds from which the first-generation plants were grown 

 were all homy, and there was no opportunity to determine correlations 

 with endosperm texture among first-generation plants. 



At the time of planting it was, of course, impossible to distinguish 

 between the seed that were pure for the homy character and those that 

 were heterozygous. An examination of the open-pollinated ears produced 

 by the second-generation plants grown from homy seeds made such a 

 separation possible. All ears that produced any waxy seeds must have 

 grown from heterozygous seeds. No correlations sufficiently large to 

 be detected in the small number of individuals available were found 

 between these two classes and other contrasting characters. 



It may be urged that the absence of coherence in the progeny of such 

 a diverse hybrid as the one here discussed may not prove that there is a 

 similar lack of coherence among crossbred individuals within the 

 variety. All maize varieties are, however, of such mixed ancestry that 

 they are in effect hybrid progenies, and even if an exhaustive study of 

 the inheritance of the characters of a narrow-bred variety should show 

 the existence of coherence the results would be beside the point from a 

 practical standpoint, for to maintain a satisfactory degree of vigor in 

 maize a condition of mixed ancestry must be retained. 



INTENSIFICATION OF CHARACTERS 



The present hybrid affords an interesting sample of an intensified 

 character. One of the peculiarities of the Waxy Chinese variety is the 

 scorpioid top. In plants which exhibit this character the leaf blades of 

 the upper nodes are monostichous and erect, and the tassel is curved to 

 one side. The curvdng of the tassel w^as originally interpreted as a direct 

 result of the monostichous arrangement and erect blades. The manner 

 in which this complex of characters reappears in the hybrid with the 

 Esperanza variety shows that, although always associated in pure 

 Chinese maize, they are separable and each may be inherited independ- 

 ently of the others. The curved tassel supposed to be merely the result 

 of the other characters may not only occur alone — that is, in plants with 



