100 



SHINKISHI HATAI 



100 



200 250 300 350 400 



Chart 1 Showing the heart weight of the male albino rat according to body 

 weight. The observed weights are represented by 134 male rats. 

 • Observed weight. — — Calculated weight. 



1. Heart? The growth of the heart in weight is represented 

 by the following formula: Weight of heart = 



0.0026 (body weight + 14) + 0.249 log (Bd. wt. + 14) - 0.336 



The constants of the fomiula were determined from 134 male 

 rats and the relation between observed and calculated values is 

 shown in chart 1. The greater fluctuation which occurs in the 

 rats of larger size has already been noted and explained. As has 

 been mentioned earlier, variations in body growth alter more or 

 less the relation between heart weight and body weight. The 

 heart weight is usually high when the rat is small for a given age 



- The weight relation between heart and body has been examined by numerous 

 investigators at various times. A list of important papers, as well as a table 

 which illustrates this relation found in the various mammals is given by Joseph 

 ('08) including his own extensive observations on dogs of various sizes. 



