2 Pearl and Bartlett. 



said that in such cases as these is to be found what is apparently 

 the best existing evidence that the continued selection of minute 

 fluctuating variations has a cumulative effect. It is, therefore, of 

 the greatest importance to subject this evidence to the most careful 

 scrutiny, and to make a thorough experimental analysis of the method 

 of inheritance of these invisible chemical characters. 



It is the purpose of the present paper to give the results of a 

 study of the inheritance of certain invisible chemical characters in 

 maize. The problem dealt with is this: Do such characters as the 

 nitrogen content, sugar content, starch content, ash content, etc., of 

 maize behave as unit characters, showing the Mendelian phenomena 

 of dominance, recessiveness and segregation? If they do so behave 

 another category of attributes of living things wül have been shown 

 to conform to Mendel's fundamental generahzations. Correns (13) in 

 his classical memoir on maize hybridization and other workers have 

 dealt with starchy and sugary endosperm, but not with the segregation 

 of other chemical characters. 



Material and Methods. 



Since 1907 the Department of Biology of this Station has been 

 engaged in the experimental breeding of several strains of maize. Two 

 of these furnished the material for the present investigation. One of 

 these was a fine grained, white, sweet (or "sugar"), maize (Zea mays 

 saccharata). The other was a yellow "dent" variety. Both were 

 imnamed varieties. In the work of the Station they have been given 

 respectively the names of their original growers from whom the foun- 

 dation stock for the breeding experiments was obtained. The sweet 

 corn^) used in these crossing experiments has been thus designated 

 as "Dennett", and the dent corn as "Cornforth". These names have 

 no significance except that of convenience in reference. 



A detailed account of the history and characteristics of sweet 

 com of the Dennett strain has recently been published (2) and need 

 not be repeated here. It may merely be said that the corn is a fine- 

 grained, early maturing, white sweet corn, bearing ears of fine quali- 

 ty2). It has been rather closely inbred for a long time (15 to 25 years) 



1) The word "corn" is used in this paper in the American sense, meaning 

 "maize", and not in the English'sense, meaning "grain". 



2) Corn of this strain and from seed bred in the Experiment Station plots took 

 first and second prize in the world class for sweet corn at the National Corn Exposition 

 in 1911. 



