1 Witoto is spoken by 80 or more families of Indians inhabiting the tributary rivers north of the Amazon from Iquitos, Peru, to the Colombian border and is divided into three major dialects which are mutually intelligible to varying degrees. Practically all the Witoto people of Peru have been transplanted from their original habitat between the Putumayo and Caquetd Rivers in Colombia about 20 years ago. There are estimated to be between 4,000 and 5,000 Witotos still in Colombia, but we have had no access to them thus far. The material of this paper is from the Muinani dialect spoken by approximately 12 families situated on the Ampiyacu River in Peru, a little above the site of Pucaurquillo, and was gathered during field trips in the years 1952-4 under the auspices of the Summer Institute of Linguistics. The chief informant for this material has been Ramon Zeballo Dia. The author wishes to acknowledge especially valuable help in his field work by Olive Shell, Wesley Thiesen, and Eugene Loos. The present paper was written in the workshop of the Summer Institute of Linguistics at the University of Oklahoma, 1955. The author is indebted to Viola Waterhouse for assistance in the organization of the data. 2 e and o are used as orthographic symbols for phonetic [e] and [a]. efode he grew old, makaoiakade he wants to walk much, uiiai many parrots, hiiauai many barbasco roots, rauaioiakade he always wants to hunt far off. Clusters of two or three vocoids are most common. Certain clusters of two vocoids3 differ in timing in different situations. It is the interpretation of these differences which constitutes the