198 



GROWTH OF PARTS 



both absolute and as a percentage of the cranium. Thus by 

 getting the weight of the fresh mandibles in any case it is possible 

 by the aid of table 135 to compute approxmiately the weight of 

 the cranium. After 100 grams this percentage relation varies 

 but slightly, though it tends to increase up to a body weight of 

 200 grams, after which it slowly dimmishes. 



TABLE 136 



Shoiving growth changes in the blood in rats of increasing age {body iceight) . Sexes 

 combined — based on tables I and II, Chisolm {'11) 



3. Teeth. For the data on the growth of the incisor teeth 

 (Addison and Appleton, '15), see chapter 3, pp. 53 and 54. 



4. Blood. By means of a formula (21) based on his observa- 

 tions, Chisohn ('11) was able to compute the volume of 

 the blood in rats of different body weights (Table 136). Hatai 

 (MS '14) has added two formulas (21a) (21b) based on that of 



