414 p. W. WHITING 



D. Analysis of the gradations of sooty base 428 



E. Reversal of dominance of sooty by black 430 



III. Summary and general discussion 434 



A. The masking of a Mendelian difference by environment 434 



B. Reversal of dominance 435 



C. Analysis of a case of continuous variation 435 



D. The physiology of color production 436 



I. INTRODUCTION 



A. Distribution and taxonomy 



The Mediterranean flour-moth^ Ephestia Kiihniella Zeller, is 

 widely distributed and very destructive to stored cereals. It 

 was noticed in Paris in 1840 and in Constantinople in 1872. An 

 outbreak of the pest occurred at Halle, Germany, in 1877, where 

 it was supposed to have been introduced with some American 

 wheat. The American origin was assumed by European writers 

 for a number of years, but it is probable that the insect was 

 rather widely distributed in Europe for some time, being noticed 

 only when it became especially abundant and troublesome. It 

 was not officially reported in America until 1889 (Cdnada). 



The insect belongs to the subfamily Phycitinae of the large 

 family Pyralidae. Its nearest important relatives are the dried- 

 currant moth, Ephestia cautella Walker, the chocolate moth, 

 Ephestia elutella Hiibner, and the Indian-meal moth, Plodia 

 interpunctella Hiibner, 



In June, 1877, Professor Kiihn, of the university at Halle, 

 sent a number of specimens to Zeller whose description appeared 

 in 1879. It is thought advisable to quote the original description 

 of the moth since the taxonomic type agrees with the genetic 

 type as treated in the present paper. Color characters with 

 which this paper is concerned have been placed in italics in 

 Zeller's description quoted below. 



Major, alis elongatis, ant. cinereis, strigis 2 obsoletis dilutioribus, 

 obscurius marginatis: priore ante medium posita, oblique, subserrata, 

 posteriore superne fracta, margin! postico nigro-punctato admota, 

 pundo venae transversae nigro gemino saepe in strigulam mutato, umbra 

 subfasciata ab eo introrsus ad dorsum demissa; post, albidis, sub- 

 hyalinis, ramis venae medianae griseis. cf 9 



