1908] LUTZ — CRIOCERIS ASPARAGI 51 



and middle spots. It will be seen in the figure that the gradation from a to 6" is perfect, 

 the melanic pigment disappearing last (or coming in first, according to the view-point) 

 from a small dot in the centre of the band of union. Furthermore, the two elytra 

 of a single insect occasionally show the two extremes of this range and the inter- 

 mediate combinations are common. This phenomenon is not illustrated in the figure. 

 At first sight this is hopeless from a Mendelian standpoint. It was found, however, 

 that "spots united" is, within limits, recessive to "spots distinct" in the Mendelian 

 sense. 



A female of pattern a, mated with a male c on the left elytron and e on the right 

 (DD X RR) gave 37 offspring only one of which had any sign of union of the spots. 

 The latter had the spots distinct on one elytron and only slightly joined on the other. 

 Another similar mating gave 42 in 47 offspring with no sign of union of the spots. 

 The remaining 5 had a very slight joining on one elytron. A female having e on the 

 right and b on the left by a male b on the right and c on the left (RR X RR but with 



a d c d e 



Variation in the Color Pattern of Crioceris usparagi. 



the recessive characteristic only slightly developed) gave 16 offspring all but one of 

 which had the spots more or less united. Eight matings of spots united X spots 

 united gave 132 offspring of which only 3 had the spots distinct. Four matings of 

 DR X DR were obtained. The result was spots distinct : spots united : :11:6, 

 22 : 9, 34 : 13, and 15 : 7, or a total of 82 : 35. Three matings of DR X RR gave spots 

 distinct : spots united : : 8: 8, 3 : 3, and 13 : 12, or a total of 24 : 23. These results 

 are surprisingly close to Mendelian expectation. Ten matings of a X a (DD X 

 DD) gave 285 oft'spring only 6 of which had the spots at all joined. 



Thus we have here a good case of a perfectly graded variation obeying rather 

 closely the Mendelian law. Spots joined, even slightly and on one elytron only, 

 marks a "pure" recessive individual. However there are variations in the relative 

 potencies of the allelomorphs such as have been found in the cases of height or nostrils 

 in chickens, abnormal wing veins in Drosophila and other characters. Some of the 

 interesting problems suggested are: (1) Is pattern c, for example, dominant over 



