66 Annals Efitoniological Society of America [Vol. XI, 



whether dorsalis is not antedated by a European name for the 

 same form. These questions will evidently have to be left to 

 European dipterists. 



The color variations described fall in the same class as a 

 number that have been studied in Lepidoptera (for instance see 

 a series of articles by Standfuss in The Entomologist, XXVIII, 

 1895, and a translation of Weismann's experiments in the same 

 journal the following year by W. E. Nicholson), in which low 

 temperature during the pupal period causes the colors to be 

 darker. This may normally affect one brood of a double- 

 brooded species, or it may be climatic rather than seasonal, 

 affecting all the individuals living in the colder region. Even 

 the absence of the pale form of Cerodonta in the west in mid- 

 summer accords with butterfly experiments, in which the pale 

 form can be made dark by cold, but the dark form cannot be 

 made pale by heat, indicating that the dark is the primitive 

 type, the pale a comparatively recent modification. 



While the subject has not been systematically studied 

 except in Lepidoptera, some observations in other orders agree 

 well; for instance, Horn (g) says of the Clerid beetle Trichodes 

 ornatus. "As a rule, the hotter the climate in which the spec- 

 imens were native, the greater the extent of the yellow color. 

 ... In colder, and especially damper climates, the blue color 

 predominates." 



REFERENCES. 



(a) Loew, Centuries, ii, 98. 1863. 



(b) Macquart, Hist. Nat. Dipt., ii, 615, 1835. 



(c) Rondani, Dipt. Ital. Prod, iv, 10, 1861. 



(d) Schiner, Wien. Ent. Monatsch., vi, 434, 1862. 



(e) Melander, Jour. N. Y. Ent. Soc, xxi, 249, 1913. 



(f) Malloch, Annals Ent. Soc. Amer., vi, 331, 1913. 



(g) Horn, Ent. News, ii, 7, 1891. 



