No. 626] SHORTER ARTICLES AND DISCUSSION 



THE MORPHOLOGICAL BASIS OF SOME EXPERI- 

 MENTAL WORK WITH MAIZE 



Of all the plants that have been made to contribute to our 

 knowledge of the principles of evolution and heredity in the last 

 twenty years, probably none holds a more conspicuous place than 

 Indian corn. The technique of its manipulation is compara- 

 tively simple, and it exhibits an extreme variability, which is 

 almost unique in extending to the endosperm ; the behavior of a 

 large number of i1»s characteristics has been found amenable to 

 a Mendelian interpretation and has aided materially in estab- 

 lishing present-day views of heredity. Indeed, maize shares 

 with Pisum the distinction of having been the means of the estab- 

 lishing of Mendelism itself, for it was in connection with their 

 work on maize that Correns and De Vries discovered Mendel's 

 paper. Since then its genetic behavior has been studied in detail 

 by a number of investigators, and there is probably no other one 

 plant that furnishes such a wealth of material illustrative of the 

 principles of heredity. 



The writer has in recent years had the opportunity of examin- 

 ing in more or less detail this same plant from the morphological 

 point of view, and it has been found that we are far more famil- 

 iar with the Mendelian behavior of some of its characteristics 

 than we are with the characteristics themselves. This has led to 

 some results illustrative of the need of very close coordination 

 between genetics and morphology. 



In one of the numerous experiments made by East and Hayes, 

 an attempt was made to interpret the Mendelian behavior of 

 the irregularity of the rows of grains on the ear of corn. The 

 ratios produced in the breeding experiments^ were not very sig- 

 nificant, and, after suggesting the possibility of " monohybridism 

 with reversed dominance," "fluctuating dominance," etc., they 

 finally conclude that "it seems probable that a more complex set 

 of conditions exists." 



If, as is suggested, this irregularity is similar to that in Coun- 

 try Gentleman sweet corn, it was probably another set of con- 

 ditions that caused the trouble. As the writer has since pointed 

 out,- the irregularity in the rows of this variety is the more or 

 less complete expression of a ver\- definite and comparatively 

 simple state of atfairs. Each female spikelet of ordinary maize 



1 "Inheritance in Maize," Bull. Conn. Agr. Expt. Sta., 167, 1911, p. 132. 



2 "The Morphology of the Flowers of Zea Mays," Bull. Torrey Club, 43: 

 127-144, 1916. 



