Bijkomende hoorn bij rhinocerossen

Blyth mentions that there may be a tendency in all rhinoceros species to develop an additional horn. This extra horn, situated behind the usual one, always remains small. An example was the large female R. indicus in London Zoo. Raffles mentions a third horn sometimes found in R. sumatranus, and Andersson in Lake Ngami recalls a third horn in the common African species.