30 COLORATION IN POIJSTES. 



The distribution of lots is as follows (fig. [4) : 



The extent of correlation here is rendered more striking still by sub- 

 dividing Classes A and C. In Lot i most of those included in Class A 

 have the median stripe reduced to a mere line, which in some cases 

 becomes obsolete at one or both ends. In Lot 2, Class A, there is no 

 tendency toward an obsolete condition in these lines. In Class C the 

 specimens belonging to Lot i do not in general show as broad stripes as 

 do those belonging to Lot 2 ; so that were we to make additional classes 

 for the extremes — X to include specimens where the stripes are narrower 

 than the narrowest of Lot 2 and often obsolete at one or both ends, and Y 

 to include specimens whose width exceeds the maximal width in Lot i — 

 we should find the following distribution : 



The distribution of males and females in the foregoing classes is 

 shown as follows : 



From this it is apparent that there is an approach to sexual dimor- 

 phism in the markings of the metathorax. This holds true for the 

 whole collection of over 1,200 specimens. For a given condition of 

 the abdomen the metathorax of the male is invariably more melanic 



