102 



GROWTH OF PARTS AND ORGANS 



The weight of both testes on body weight. Technic: The epi- 

 didymis was removed before the testes were weighed. The 

 graph in chart 22 and the values in table 70 were determined by 

 formulas (22), (23) and (24). Hatai ('13); Jackson ('13). 



.35 



.30 



.25 



.20 



.15 



.10 



.05 



THYMUS GLAND 

 weight grams 



35 



Age in days. 



280 



300 



350 



30 



25 



20 



15 



10 



05 



Chart 23 Showing the weight of thethymus of the albino rat according to age. 

 The observed weights are represented by 229 males (164 Jackson and 64 Wistar) 

 and 207 females (179 Jackson and 28 Wistar). Table 72, formulas (38) and (39) . 



Observed weight male, O female, computed weight. 



Weight of thymus on age. In the case of the thymus the data 

 are more useful when presented according to age than when pre- 

 sented according to body weight. 



Technic: In preparing the thymus care must be taken to dis- 

 sect away the large lymph glands as well as the fat lying about 

 it. The records by Jackson ('13) have been combined with those 

 from The Wistar Institute. The graph in chart 23 and the values 

 in table 72 have been determined by the formulas (38) and (39). 

 No weight difference according to sex has been noted. Hatai 

 ('14); Jackson ('13). 



