^* This research was supported by ESRC grant R000275283. I am grateful to Quentin Gausset for discussion of many of the issues presented here, to Baba Jual and David Zeitlyn for assistance in doing the Njerep census, and to the organizers of the Symposium on Language Endangerment in Africa for inviting me to present this aspect of my work at the Symposium.

[1] Different languages of course used in different social situations: e.g. Fulfulde in the market or when talking to strangers, or possibly French or English when talking to Europeans.

[2] Subsequent documentation of the E. Mambila lects has provided further supporting evidence for this.

[3] The area of the Tikar Plain now inhabited by Mambila people was also apparently once Tikar land (Zeitlyn 1992). It appears in these cases the Tikar were driven out, or at least replaced, by the Mambila.