ALBINO RAT VISCERA, GLANDS, EYEBALLS! WEIGHTS 105 



Chart 6 Showing the weight of alimentary tract of the male albino rat ac- 

 cording to body weight. The observed weights are represented by 112 (Jackson) 

 rats, below 50 grams in body weight, and 82 (Wistar) rats, above 50 grams in body 

 weight. 



• Observed weight. Calculated weight. 



The cause of this enlargement, as found in the rat, has not been 

 studied. 



6. Alimentary tract. The growth of the aHmentary tract in 

 weight is represented by the following formula: Weight of ali- 

 mentary tract = 



0.0245 Bd. wt. +4.720 log (Bd. wt. +7) -5.753 



The constants of the formula were determined from 194 male 

 rats and the relation between observed and calculated values is 

 shown in chart 6. Despite the fact of some difficulty in removing 

 this organ, the weight of the aHmentary tract is highly uniform 

 in the rats up to 150 grams in body weight, but beyond this pe- 

 riod it becomes decidedly variable owing to the greater frequency 

 of intestinal disturbance. This intestinal disturbance seems to 



