834 EXPERIMENT STATION RECORD. 



the correlation between parts of the corn plant and the value of certain com- 

 binations of characteristics, (2) the modifications which take place in the corn 

 plant as a result of a change in environment, and (3) the relations between the 

 amount of water used, the leaf area, and the growth of the plant 



Observations were made on many individual plants during 1902 and succeed- 

 ing years. Tables present data dealing with the following points : Leaf area, 

 height of stalk and ear, number of nodes, ear nodes, length of shank, weight of 

 stalk, ear, and total plant, ratio between weight of stalk and weight of ear, and 

 ratios of leaf area to total weight, weight of ear, and weight of stalk. 



It was found that when individual plants were considered there was no 

 marked relation between leaf area and weight of corn produced or total weight 

 of plant. In different varieties, hawever, there was quite a difference in the 

 ratio of stalk to ear, the ratio being 0.74 in the case of Pride of the North and 

 1.15 in Hogue Yellow Dent. The amount of leaf area to 1 gm. of dry weight 

 was also found to vary, ranging from 2.3 sq. in. for Minnesota No. 13 to 2.6G sq. 

 in. in case of Hogue Yellow Dent. 



Corn growTi from Iowa seed was taller and made a larger stalk than that 

 grown from Nebraska seed, in an acclimatization test. 



Tables show the degi'ee of correlation between the different parts of the corn 

 plant. 



The author draws the following conclusions in regard to useful characters 

 under observation : (1) "A low relative leaf area seems desirable." (2) "Assum- 

 ing high proportion of com to be desirable, a short shank is preferable." (3) 

 " Selection of high or low ears does not affect yield." (4) "Medium in stout- 

 ness of stalk would seem best." 



Data given show that the relative size of plants was not transmitted to any 

 degree, and the author states that variation in size of plant is not inherited but 

 is due to some local cause, which indicates that size of plant is so modified by 

 local conditions that potential qualities can not be judged from the individual. 

 Taking plants as found under field conditions no characters have been found 

 closely enough correlated to indicate ability to yield. The inherent characters 

 can only be determined by a study of a sufBcient number of progeny. 



Data collected during a 3 years' test show the relation of water loss to leaf 

 area and dry weight. The plants experimented with were grown in potometers 

 under uniform conditions as to fertility, quantity of soil, and available water. 

 The results show that in various types of corn the amount of water transpired 

 by the plant is correlated to some extent with leaf area. 



Genetic correlation and spurious allelomorphism, in maize, R. A. Emebson 

 (Neiraska Sta. Rpt. 1910, pp. 58-90, figs. 9). — ^A discussion is given of color 

 correlations in general showing that it is often very difficult to determine 

 whether characters are genetically correlated or not. In crosses of varieties 

 of green-podded, green-leaved beans with yellow-podded sorts also having 

 green leaves, the Fi generation had green pods and leaves and the F2 generation 

 showed typical Mendelian behavior, thus giving evidence that pod color and 

 leaf color in beans are not genetically correlated. However, in another cross 

 between the green-podded, green-leaved sort with a variety bearing " golden " 

 leaves as well as yellow pods, the F2 generation separated into 2 distinct classes, 

 showing correlation. 



Tables state the results of work done in trying to find correlated colors in 

 maize. The Fi generation plants were taken from the open pollinated parent 

 and the data show the color of cob, pericarp, and in some cases of husks, 

 silks, and anthers. The F2 generation was selected from the self pollinated Fi 

 generation and gives similar data in regard to colors. " In every case but 4, 

 included in the table, only 2 types occurred in the F2. One type always had 



