DISTRIBUTION OF BUTTERFLIES IN THE NEW WORLD 365 



centers of origin for many species and genera of butterflies have 

 often been places where invading species have encountered many 

 new, unoccupied habitats, for, it is generally assumed, adaptive 

 speciation is rapid and extensive in such places. Such a process has 

 probably led to the evolution of the endemic genera of Satyridae in 

 the Andes, during the relatively recent grand uplift of the Cordillera. 

 A similar basis may be inferred for the development in northern 

 regions of new species of Colias, Argynnis, and other genera that 

 probably invaded the disturbed lands of North America, some in 

 relatively recent time. Such centers of origin are areas where diverse 

 genetic types on new arrival have found readily available habitats 

 for their occupancy. The trial and error system of natural selection 

 probably succeeds best under such conditions. 



BIBLIOGRAPHY 



Below is a partial compilation of the literature that has provided a 

 large part of the data for the present digest. Nearly every paper published 

 on American butterflies is important in providing geographical or ecologi- 

 cal information. A bibliography such as this cannot, however, list every 

 paper seen or read. The author's observations have also been essential in 

 providing accuracy on the altitudinal and geographical distributions in 

 Alaska, the Northwest Territories, the Yukon Territory, Alberta, and 

 British Columbia, the Sierra Nevada, the Rocky Mountains, Mexico, 

 Central America, Colombia, and Ecuador. Without these observations, it 

 would probable have been impossible to have constructed the histograms. 

 Accuracy in the Mexican region is due in large part to the data of Hoff- 

 mann. The region poorest known is that of the central to southern Andes, 

 in Peru, Bolivia, Argentina, and Chile. Data obtained from collections 

 should also be mentioned, even though many of these do not give alti- 

 tudinal details. 



Barnes, William, and J. J. McDunnough. 1911-1922. Contributions to the 

 Natural History of the Lepidoptera of North America, Vols. 1-5. 

 Decatur, 111. 



Bates, Marston. 1935. The butterflies of Cuba. Bull. Museum Comp. Zool. 

 Harvard. 78: 61-258. 



Bowman, Kenneth. 1919. Annotated Check List of the Macrolepidoptera of 

 Alberta. Alberta Natural History Society, Red Deer, Alberta. With 

 revisions 1919, 1920, 1921, 1924, 1928, 1934, 1938, 1944. 



Breyer, Alberto. 1936. Lepidopteros de la Zona del Lago Nahuel Huapi 

 Territorio del Rio Negro. Rev. soc. entom. arg., 8: 61-63. 



. 1939. Uber die Argentinischen Pieriden. VII Intern. Kongr. 



Entom., Berlin, 1938: 26-55. 



