June 19, 1916 Correlated Characters in Maize Breeding 445 



sheath in the mature plant. Differences in this particular were recorded 

 by measuring the distance from the top of the uppermost sheath to the 

 origin of the lowest tassel branch, the measurement being expressed as 

 a minus quantity when the base of the branch was included in the sheath. 



This character is especially subject to environmental changes. Un- 

 favorable conditions, such as drought occurring late in the season, will 

 prevent the elongation of the upper intemodes to such an extent that 

 all varieties may show a minus exsert. Comparisons must therefore 

 be confined to plants grown in a single season in the same locality. 



The range as recorded for Waxy Chinese grown at different times is 

 from — 14 cm. to 7 cm., with the mean at — 1.31 ±0.3. In Esperanza the 

 range is from —3 cm. to 18 cm., with the mean at 6.o7±o.5. 



NUMBER OF ERECT LEAF BLADES 



In the Waxy Chinese variety the upper leaf blades are held erect 

 instead of diverging. In ordinary varieties which the Esperanza resem- 

 bles with respect to this character the upper leaf blades make approxi- 

 mately a right angle with the axis (PI. LV, LVII). As a measure of this 

 character the number of erect leaf blades was recorded. For example, 

 if the two uppermost leaves were erect and the third leaf was the 

 first to exhibit an angle, the plant was classed as 2, with respect to this 

 character. 



Recorded in this way there would be some overlapping in the parent 

 varieties, since in some Waxy Chinese plants even the uppermost leaf 

 shows an appreciable angle. In reality, however, the two types are dis- 

 tinct, for in the Esperanza not only is the uppermost leaf never erect, but 

 it is seldom borne at less than a right angle with the stalk. 



ANGLE OF TASSEL AXIS 



In the Esperanza variety the tassel is always erect. In the Waxy Chi- 

 nese plant the tassel is usually curved or declined (PI. LV, LVII). This 

 character is variable in the Chinese, some plants having the tassel per- 

 fectly erect. The tendency, however, to an inclined tassel, as it appears 

 in the hybrid, may properly be ascribed entirely to the Chinese variety, 

 no similar tendency ever having been observed in any Esperanza plant. 

 The character was measured by estimating the angle which the branch- 

 ing space, or that portion of the axis of the tassel between the lowest and 

 highest branch, made with the main stalk. In the pure Waxy Chinese 

 variety this character appears definitely associated or physiologically 

 correlated with the following character of *'one-sidedness." 



ONE-SIDEDNESS 



One of the most striking peculiarities of the Waxy Chinese variety of 

 maize is the displacement of the leaf blades from the usual distichous 

 arrangement, with the result that a number of the upper leaf blades are 



