112 



SHINKISHI HATAI 



0.5 



0.1 



Chart 12 Showing the weight of eyeballs of the male albino rat according to 

 body weight. The observed weights are represented by 149 male rats (Jackson) 

 • Observed weight. — Calculated weight. 



of enlargement. In some instances this enlargement amounts 

 to almost ten times the average value. From the data here 

 used, all hypertrophied cases were excluded. The enlargement 

 of the gland can be easily recognized not only by the size, but 

 also by the color. The color of the normal gland is pink while 

 that of the abnormal gland is milky owing perhaps to an exces- 

 sive accumulation of the colloidal material. A slight acquaintance 

 removes any difficulty in distinguishing the abnormal from the 

 normal gland, 



12. Eyeballs. The growth of the eyeballs in weight is rep- 

 resented by the following formula : Weight of eyeballs = 



0.000428 Bd. wt. + 0.098 log Bd. wt. - 0.041 



The constants of the formula were determined from 149 male 

 rats. The relation between observed and calculated values is 

 shown in chart 12. The entire data used were furnished by Dr. 

 Jackson and obtained by him from the rats belonging to the col- 

 ony kept at the University of Missouri. 



