identified, and placed in envelopes. The teeth are then counted, using natural transmitted 



are ground lengthwise by holding the tooth light, to determine age. 



against a mechanically turned grinding wheel. 



When the desired thickness (center of tooth) is Genital tracts .- -The condition of female 



reached, the work is finished manually on a genital tracts collected is noted at the labora- 



grinding stone. The internal annuli of the tooth tory, rather than at the time of collection. 



39 



