It is evident that the crucial factor in the economy was the amount of food stored for winter and that this food supply was a controlling influence on the size of the population, since, in bad years, people starved. At least, this was so for the Lassik, and it was no doubt true among the other groups as well. Salmon, meat, and acorns were doubtless the chief foods stored, and thus population size would have responded quite sensitively to the quantity and condition of the salmon, deer, and oak trees. _Social organization._--For social organization I have had to rely mostly on Nomland's accounts of the Sinkyone and Bear River groups (1935, 1938). The primary social unit among the California Athabascans was the simple family, including a man, his wife, and his children. Although polygyny was known, at least among some groups, it was rare, and the possessor of two wives was reckoned a rich man. Most marriage was by purchase; the levirate and sororate were common. Divorce was also common and might be obtained by a man because of his wife's barrenness, laziness, or infidelity. The next social group, larger than the family, was the tribelet. Kroeber (1932, p. 258) has defined the tribelet as follows. Each of these [tribelets] seemed to possess a small territory usually definable in terms of drainage; a principal town or settlement, often with a chief recognized by the whole group; normally, minor settlements which might or might not be occupied permanently; and sometimes a specific name, but more often none other than the designation of the principal town. Each group acted as a homogeneous unit in matters of land ownership, trespass, war, major ceremonies, and the entertainment entailed by them. This definition, given for the Pomo, fits the Athabascan area very well. Merriam usually refers to these groups as "bands," while Goddard calls them "subtribes." In the body of this paper I use the word "band" when quoting or paraphrasing Merriam, otherwise I call them "tribelets." The tribelet was the largest corporate group in the area. A larger group, which I call the tribe, has been identified by most ethnographers. This latter group ordinarily had no corporate functions, unless it happened to be coterminous with, and therefore indistinguishable from, the tribelet. The tribe, as the term is used here, was a group of two or more tribelets--or occasionally one single group--with a single speech dialect, different from that of their neighbors. The tribe was also culturally uniform, but not necessarily distinct from its neighbors in this respect. The similarity between people of a single tribe evidently gave them a feeling of community but had no further effect on their social or political organization. The following tribes have been identified in the Athabascan area, each including several tribelets, except for the Bear River tribe, which consists of one single tribelet.