—34— 



what was once a very rare variety or aberration. Secondly, it is well to 

 remember that both Pieris rapoe and P. venosa have yellow aberrations, 

 and even possibly (as I have argued in "Entomologist," 1888, p. 112,) 

 came from yellow ancestors, — and thirdly, in one species at least of 

 Anfhocharis {A. cardamines) there is an aberration (ab. aureoflavescens, 

 see "Entomologist," 1888, p. 189), in which yellow takes the place of 

 orange. 



Prepara/oiy s/ages. — Dr. T. A. Chapman has an excellent paper 

 C'Ent. Mo. M.\G.," 1888, p. 257), in which he compares the egg of ^. 

 cai-damines with that of Pieris rapoc — pointing out that the egg of the 

 former becomes orange, while that of the latter is never darker than a 

 pale yellow — and further, that the eggs of cardamines are laid on the 

 flower-heads. Having the eggs of no other Pieris at hand, he goes no 

 further with his comparison, and it might be supposed that these diff'er- 

 ences were in some sense generic. But it is not so : Pieris protodice is 

 very common in Custer Co. , Colorado, and lays its eggs profusely on 

 Arabis, Sisymbrium and other cruciferous plants. These eggs are orange, 

 and are nearly always laid on the floiver-heads of Arabis, though also 

 frequently on the stem and leaves of Sisymbrium. 



Anthocharis ausonides (var. co/oradensis, H. Edw. ) flies herein 

 May, and lays its eggs in the same situations as P. protodice. This year 

 I sent Mr. W. H. Edwards a number of young larvae, presumed to be 

 \\\o^Q^ o{ protodice — and certainly seeming all to belong to the same 

 species. But on the ist of July he wrote: '"Out o^ ray protodice larviie I 

 got on the 30th (June) several proper pupas (a (^ protodice emerged fiom 

 one of them some days later) and one of Ant/i. ausonides. I had not 

 noticed any difference in the lar\ie : I thought .^omeiimes some were 

 blacker than otliers — more black hairs." So it wifl be seen that in the 

 earlier stages P. protodice and A. ausonides have the closest reseml;lance 

 — the larvae, in fact, are not distinguishable. 



From these facts, I am inclined to believe {h'M AnthoJiaris ausonides 

 on the one hand, and Pieris pt otodice and its allies on the other, come 

 nearest to the prnnitive stock from wliich both arose — and it is favorable 

 to the idea of the antiquity oi ausonides that it is ihe one species of its 

 genus in America ranging to the far north — even Alaska. As^uming this, 

 we are perhajis at liberiy to ct)nstruct a hypotheiical Protopieris, and 

 imagine a butterfly inhabiting the American continent ages ago, in shape 

 somewhere between the modern Pieris '^\\(\ LeucopJiasia — perhaps doubie- 

 brooded — in markings, with a central black spot and dark apical patches 

 to the fore wings, on the underside gray, maibling on the secondaries 

 (for the green I take to be a suisequent arrangement of the }'ellow and 

 black scales*) — in color, possibly safiYon or brimstone yellow, though 

 probably already white, or partly so. 



West Cliff, Custer Co. , Color.\do, July, 18S8. 



* And the green veining of the underside of Pieris napi is of tlie same nature — 

 in neither case is there ideally any green pigment. 



