According to the in-depth observer van der Burgt, the language of the Kitwa among the Rundi speak a language of their own (in addition to Kirundi itself) which is not understood by the neighbouring Rundi (Watussi and Wahutu) speakers ( van der Burgt, J. M. M. 1902: 79 , van der Burgt, Joannes Michael M. 1903: 73-74 ), and has the same grammar as Kirundi but is lexically different (the bulk of which is nevertheless of Rundi origin!). This language is missing from E16/E17/E18/E19/E20/E21/E22/E23/E24/E25/E26/E27/E28. (Later researchers (see Seitz, Stefan 1970: 39-42 ), in particular Schumacher, Peter 1949, 1950: 253-256 , have found accented varieties of Kirundi spoken by the Batwa, but not so different as to be unintelligible. The variety described by van der Burgt, J. M. M. 1902: 79 must therefore either have been assimilated in the meantime or have been too subtle to discern.)