100 



GROWTH OF PARTS AND ORGANS 



6. The third group of the organs here considered is formed by 

 those the growth of which is represented by a sinuous graph in 

 which the most marked rise appears shortly before puberty. These 

 organs, so far as examined, are the ovaries, the testes and the thymus. 



350 



400 



450 



50 100 160 200 250 : 3OO 



Chart 20 Showing the weight of suprarenals of the albino rat according to 

 body weight. The observed weights are represented by 92 (Jackson) male rats 

 below 50 grams in body weight, and 53 (Wistar) male rats above 50 grams in 

 body weight; and 84 (Jackson) female rats below 50 grams in body weight, and 

 29 (Wistar) female rats above 50 grams in body weight. Table 71, formulas 

 (30) and (31) . 



Observed weight, male. O Observed weight, female. 



Calculated weight, male. Calculated weight, female. 



The weight of both ovaries on the body weight. Technic: The 

 ovaries must be carefully dissected from their capsules and 

 from the end of the fallopian tube. When the animal is small it 

 is sometimes necessary to do this under a dissecting microscope. 

 The data collected by Jackson ('13) are those used. The graph 

 in chart 21 and the values in table 70 have been determined by 

 formulas (25), (26), and (27). Hatai ('13, '14a); Jackson ('13). 



