266 



GROWTH OF PARTS AND ORGANS 



weights at which the post-natal maximum appears. The graph 

 for each organ appears in the corresponding chart (chart 49, 

 nos. 2-21). WTiere the graphs for the two sexes are similar, only 

 that for the male has been drawTi. 



TABLE 154 

 Weight of viscera {12) 



TABLE 155 



Relative percentage weight of viscera 



By the use of the data in these tables and charts it is possible 

 to obtain a picture of the organ composition of the rat at various 

 body weights. In this series the body weights up to 250 grams 

 are normal for age — as given in table 157. 



For the details of the relations the original paper (Donaldson, 

 '23) should be consulted, but it may be pointed out here that the 

 phase of rapid growth m an organ comcides with the coming of 



