@article{jacobsen1968prehistory,
  source = {jstor},
  ISSN = {0097-8507},
  abstract = {Alternative hypotheses regarding the vowel system of Proto-Sahaptian and the transition to the two daughter languages, Nez Perce and Sahaptin, are examined. The proto-language may possibly have had a five-vowel system */i e a o u/, identical to that of Nez Perce, and already showing the same pattern of vowel harmony alternations. But a reconstruction of the vocalic system before the development of vowel harmony, whether or not this predated Proto-Sahaptian, presents several possibilities. A six-vowel system */i e e a o u/ would allow a straightforward development. A suggested three-vowel system is rejected. The possibilities of development from four- or five-vowel systems are examined, but these, while conceivable, are less plausible. Examination of the comparative evidence suggests that Proto-Sahaptian possessed the six-vowel system and may have lacked vowel harmony. Some areal similarities to such a system are noted.},
  author = {Jacobsen, William H., Jr.},
  copyright = {Copyright 1968 Linguistic Society of America},
  journal = {Language},
  jstor_articletype = {Full Length Article},
  jstor_date = {196812},
  jstor_formatteddate = {Dec., 1968},
  month = {dec},
  number = {4},
  pages = {819--829},
  publisher = {Linguistic Society of America},
  title = {On the Prehistory of Nez Perce Vowel Harmony},
  url = {http://links.jstor.org/sici?sici=0097-8507%28196812%2944%3A4%3C819%3AOTPONP%3E2.0.CO%3B2-X},
  volume = {44},
  year = {1968},
}