PHYSICAL TRAITS 21 



Lewis stated that they were stained by coffee. I surmise, 

 however, that this was not the case and infer from informa- 

 tion gleaned from other sources that they had been stained 

 by some African berry or fruit. In the course of the past 

 eight months they have become appreciably lighter and the 

 permanent teeth are now almost white. In August, 1923, 

 and the same is true at the present writing, June, 1924, Chim 

 possessed his full quota of milk teeth, twenty, and in addi- 

 tion his first pre-molars, making a total of twenty-four. 



As to the age of this male chimpanzee it may be remarked 

 that fourteen months in August, 1923, Mr. Lems' statement, 

 is probably an underestimate. It is not Hkely that the ani- 

 mal would exhibit permanent teeth before the end of the 

 third year. I therefore hazard the guess that he is now 

 (June, 1924) more than three years of age. 



The accompanying table (see page 22) presents several 

 physical measurements for each of the animals made on De- 

 cember 19, 1923. The same measures were repeated for 

 Chim on March 25, 1924. Some fifty additional measure- 

 ments were recorded for future reference. 



It may be said in passing that the making of reliable an- 

 thropometric observations on chimpanzees is not perfectly 

 simple and easy. In the first place it requires considerable 

 time and patience to accustom the animals to the instru- 

 ments, and thereafter to acquire such skill in their use that 

 reasonably trustworthy observations can be made. 



The characters measured and the procedure employed are 

 described for human subjects by Hrdlicka (8). The meas- 

 uring devices consisted of Hrdlicka head calipers, small and 

 large straight calipers, Starrett steel tape, graduated in milli- 

 meters, scale, and home-made stadiometer. The latter was 

 constructed with sliding foot-piece so that the animal could 



