THE CANADIAN ENTOMOLOGIST. 359 



being like fig. j of Prof. Riley's series. This astonished me because of my 

 northern experience, and I scrutinized all that I saw, even though 1 did 

 not bottle them, being on the watch for an immaculate specimen. All pure 

 white moths found, however, proved to be virgitiica, and of these I took 

 but three. Thus it seems improbable that Dr. Fyles's idea is correct, and 

 that a second brood in the south is spotted. These insects captured by me 

 in the middle of March, in a backward season, can hardly have come from 

 larvse hatched the same year. In regard to size. Prof Smith's idea does 

 not hold, for the largest specimen taken is slightly smaller than my 

 smallest northern specimen. 



Next, a word as to the distribution of congrua. Prof. Smith contends 

 that congrtia is not recorded (except Walker's Georgia specimens') from the 

 south. It happens that the set in my collection is peculiar in the light of 

 this statement. I have one male, given to me years ago by Miss Emily 

 Morton, still bearing her label, New Windsor. Then, one male and two 

 females from Nashville, Tennessee, and lastly, two males taken by myself 

 in March at Summerville, So. Ca., so that of my six specimens, five are 

 southern. 



A few more words as to size and maculation, and I have done. The 

 study of variable insects is naturally more interesting than where we have 

 to consider species fairly constant in pattern ; but there is a point which I 

 desire to make which I have not seen noted by any other authors, though 

 not improbably it has been. I believe that there is a type of pattern in all 

 species, and that this type will be constant, regardless of the variability. 

 Thus, in a spotted species certain spots will be constant whether accom- 

 panied by others or not. If we have to deal with a species sometimes 

 spotted and sometimes immaculate, then the immaculate form must be the 

 type, and the spotted forms merely variations, though among these spotted 

 variations there may be found a constancy as true as with a normally 

 spotted species. Can we apply this rule to congrtia and ciinea ? Let us 

 call congnui a spotted species and cunea an immaculate species, and weigh 

 the result. Dr. Fyles records a long series o{ congrtia and describes the 

 variations of the pattern, but he has noted that on his most immacu- 

 late form there was a small black dot on the median nerve at the angle of 

 the second fork. This dot he records on all his varieties, and it is there 

 fore the constant character which prevents us from considering that the. 

 typal pattern is immaculate. Nevertheless, later he tells us that with his 



