Page:Castes and Tribes of Southern India, Volume 2.djvu/60

CHENCHU CHENCHU 44 with various other jungle tribes, they are, as shown by the following table, at once differentiated from the mesaticephalic dwellers in the plains near the foot of the Nallamalais: — The visual acuity of the Chenchus was tested with Cohn's letter E, No. 6. For clinical purposes, the visual acuity would be represented by a fraction, of which 6 is the denominator, and the number of metres at which the position of the letter was recognised by the individual tested is the numerator, e.g., :V.A=13m/6=2.16 The average distances in metres, at which the letter was recognised by the various castes and tribes examined by myself and Dr. W. H. R. Rivers, were as follows: —