Schmidt 1978), and the collection of oral traditions in order to verify the existence of various archaeological entities (Schmidt 1978). These investigations have produced enough information to outline climatic and vegetation shifts in the region, especially during the late-Pleistocene and early-Holocene periods, and have also helped in defining the major cultural entities of the region. Thus, the major theoretical orientation of most of these studies has been culture historical as well as ecological in reconstruction.

The first systematic study of the later prehistory of East Africa was started in the 1920s by louis s. leakey, who at the time was concentrating his work in the area of Lake Nakuru and Lake Naivasha in Kenya. The principal aim of his work, as was the case elsewhere at that time, was to try to reconstruct the region’s cultural history using archaeological evidence. Leakey was most concerned with looking at the origins of food production in the region. The presence of polished ax heads, stone bowls, pottery, and human burial sites in the area led Leakey to refer to this industry as Neolithic, and he named it Njoroan after the present-day Njoro township, where it was first identified. Leakey thought this culture had intruded into the area from the Sudan (L. S.B. Leakey 1931). Calling this industry Neolithic was in line with the practice elsewhere, notably in the Near East and Europe, of assigning any industries with pottery and polished artifacts to the Neolithic period. According to Leakey, the pottery, stone bowls, and polished artifacts had been used for the preparation of domesticated cereals, which meant that their presence in the region indicated the practice of some sort of agriculture (L. S.B. Leakey 1931).

Apart from reconstructing the culture sequence, Leakey was also concerned with trying to ascertain the racial or linguistic group of the makers of the cultures. Thus, on the basis of the oral history of the Kikuyu tribe, Leakey attributed these early Neolithic sites to the mythical Gumban people, who were supposed to have preceded the Kikuyu. The Gumban cultures were divisible into two, Gumban A and Gumban B. The former was characterized by pottery that was internally scored and had extensive external decoration, a motif Leakey described as basketlike. This culture was represented at the Makalia burial site and Stable’s Drift on the Nderit River. Gumban B, on the other hand, was characterized by the presence of well-made stone bowls, pestle rubbers, and obsidian artifacts as well as pottery that had a roulette decoration. The type site for this culture was the Nakuru burial site and present-day Lion Hill near Lake Nakuru.

mary leakey was the next person to concentrate on researching the Neolithic, and like her husband, she centered her work in the Naivasha and Nakuru lake basins. She excavated the Hyrax Hill cemeteries as well as an Iron Age settlement on the site, and later she excavated a Neolithic crematorium at Njoro, now commonly referred to as the Njoro River Cave. The Hyrax Hill site was a combined settlement and burial site in which males were buried with no grave goods while females were buried with grave goods such as beads, pottery, and stone vessels. In her report, Mary Leakey (1943) suggested that a site should be designated as Neolithic if it had polished artifacts, pestle rubbers, stone bowls, or systematic burials. She further argued that the presence of cultivation and/or animal husbandry in the form of domestic plants or animals was not necessary in order for a site to be considered Neolithic. This definition was later to prove crucial in the identification of new Neolithic cultures at Hyrax Hill and Njoro River Cave.

The Njoro River Cave site yielded about eighty cremated human burials and large amounts of grave goods, among which were stone bowls, grindstones, pestle rubbers, flaked stones, stone beads, stone pendants, pottery, remains of a gourd basket, and an elaborately decorated and carbonized wooden vessel. Leakey assumed that the Njoro River Cave culture had a genetic relationship with the Mesolithic culture named Elmenteitan, and she thus described the culture as evolved Elmenteitan.

Subsequent research did not yield more sites with finds similar to those of the Njoroan culture, so the term was dropped. The research, however, did reveal two more cultures—the Tumbian and the Kenya Wilton C, which were considered to be Neolithic. The Tumbian