The Mendelian Inheritance of Certain 

 Chemical Characters in Maize ^). 



By Raymond Pearl aiul James M. Bartlett. 



Introduction. 



In the work which has thus far been done along Mendelian lines 

 in the study of inheritance the characters dealt with have been, in 

 the main, either purely structural, or else somatic colors and color 

 patterns. Beyond all structural and color characters there is, a 

 further, more or less well defined, set of attributes of organisms, the 

 inheritance of which has not been subjected to experimental analysis 

 so far as we are aware. These may be called the invisible chemical 

 characters. In all agricultural work these characters are of great 

 importance. Thus to mention but a few examples; the value of sugar 

 beets is directly determined by their sugar content ; maize is of value 

 for feeding purposes in direct proportion to its nitrogen content, etc. 

 It is, of course, a well known fact that different strains and different 

 individuals within the strain, in all our agricultural plants, vary in 

 their chemical composition. On the basis of this variation a great 

 deal of work has been done in improving various plants by selective 

 breeding in respect to one or another of their invisible chemical 

 characteristics. One needs to mention here by way of illustration 

 only such conspicuous examples as the breeding of beets for increased 

 sugar content, and the work at the Illinois Station (i)-) in changing 

 the protein and oil content of maize by selection. It may fairly be 



I) Papers from the Biological Laboratory of the Maine E.xperiment Station, 

 Orono, Maine, U. S. A. No. 26. The investigations on which this paper is based 

 were carried out in the biological and chemical departments of the Station working 

 jointly. The division of labor was as follows: The work of obtaining the material 

 and the preparation of the paper were done in the Department of Biology; the 

 chemical analyses were made in the Department of Chemistry. 



ä) Numbers in brackets throughout the text refer to items in the literature list 

 at the end of the paper. 



liuiiiktive Absuinmimgs- und Vererbungslehre. VI. I 



