218 



GROWTH OF PARTS AND ORGANS 



The form of the graph is similar to that for most of the visceral 

 organs. The relation between the weight of the submaxillaries 

 and that of the body is, after 25 grams in body weight, prac- 

 tically linear. There is no indication of a sex difference so far as 

 the weight is concerned. 



Weight of the thyroid gland on body weight. Technic: Several 

 minute muscles nearly the color of the gland must be removed 



50 



100 



150 



200 



250 



300 



350 



400 



450 



Chart 42 Showing the weight of thyroid gland of the albino rat according to 

 body weight. The observed weights are represented by 42 (Jackson) female 

 rats below 50 grams in body weight, and 49 (Wistar) male rats above 50 grams in 

 body weight; and 36 (Jackson) female rats below 50 grams in body weight, and 

 27 (Wistar) female rats above 50 grams in body weight. Table 148, formula (39) 



Observed weight male, 

 served weight, female. 



Calculated weight for both sexes. Ob- 



before weighing. The data are from observations by Jackson 

 ('13), as well as from those made at The Wistar Institute. A 

 study of the data has not revealed any difference according to 

 sex and the graph therefore is for both sexes combined. The 

 graph in chart 42 and the values in table 148 have been deter- 

 mined by formula (39). Hatai ('13); Jackson ('13). 



The weight of the hypophysis on body weight. Technic: After 

 the removal of the brain, the hypophysis is readily picked up 



