116 



LAWSON G. LOWREY 



Fig. 1 contains four curves — one each for the head, Hver, and 

 brain, and one for all the viscera taken together. 



Fig. 2 contains five curves — one each for the kidneys, Wolffian 

 bodies, heart, stomach and intestines with contents, and the same 

 empty. 



1516 25 39 58 84 107 130 157 



Body Length in Millimeters 



191 215 242 262 



Vig,. 1 Curves showing the relative growth of all the viscera, the head, liver 

 and brain. These curves were secured by arranging the average percentage 

 (for the litter) which the organs form of the net body weight, according to the 

 average body length (in millimeters). In certain cases, several litters are com- 

 bined, the average of the litter averages being taken (see above). The broken 

 line at the right shows the trend of the post-natal relations, as indicated by the 

 observations on the adults. The information thus gained is only general, as 

 there are no indications concerning the age of the specimens, or the rnpidihj 

 with which the changes take place. 



Fig. 3 contains three curves — one each for the lungs, spinal 

 cord, and eyeballs. 



Fig. 4 includes curves for the gonads (ovaries and testes), thy- 

 mus and spleen. 



Fig. 5 includes curves for the suprarenal glands, thyroid 

 and pancreas. 



