118 EFFECTS OF INANITION IN THE PREGNANT ALBINO RAT. 



gained 24 per cent. Jackson (1915a) found the spleen to lose 42 per cent in rats 

 starved from 3 weeks of age to 10 weeks. In two series starved during later periods 

 (Jackson, 1915a; Stewart, 1918) there was no material change in its weight. 



In adult rats in chronic inanition the reduction in the weight of the spleen is 

 about the same as that for the whole body, while in acute inanition the loss is much 

 greater (Jackson, 1915). 



Intestines.— The intestines, with their contents, have an average weight of 0.141 

 gram and form 3.0 per cent of the body-weight (4.92 grams) in my normal newborns. 

 The empty intestines have an average weight of 0.062 gram or 1.3 per cent of the 



body-weight. 



In my prenatal controls the intestines with contents form 1.6, 1.9, 1.9, 2.4. and 



2.3 per cent of the body-weight (computed from table 5) . Thus the relative weight 



of the intestines with contents is considerably less in the prenatal controls than in the 



normal newborn rat, the difference decreasing, however, as the prenatal control 



fetuses approach their birth- weight. 



In my test rats the intestines with contents form 1.8, 2.2, 2.5, 2.4, and 2.4 per 



cent of the body-weight in Groups I to V, respectively (computed from table 5.) 



Thus the relative weight of the intestines with contents is slightly higher in the test 



rats than in the prenatal controls. 



The empty intestines in my prenatal controls form 0.64, 0.75, 0.76, 0.93, and 



1.60 per cent of the body-weight in Groups I to V, respectively (computed from 



table 5). Thus it is evident that the relative weight of the empty intestines is 



lower in the fetus, increasing progressively up to birth. 



In my test rats the empty intestines form 0.60, 0.71, 0.95, 0.82, and 0.90 per 



cent of the body-weight in Groups I to V, respectively (computed from table 5). 



Therefore the relative weight of the empty intestines in the test rats is slightly less 



than that of the prenatal controls. 



The absolute weight of the intestines with contents, in the test rats, exceeds 

 that of the prenatal controls in Group I, II, III, and V by 24, 17, 31, and 2 per cent, 

 respectively. In Group IV the absolute weight is 0.06 per cent lower in the test 

 rats. From the foregoing it is evident that the intestinal contents in the smaller 

 test rats markedly exceeds that of the smaller prenatal controls (fetuses), this 

 difference disappearing in the larger rats, i. e., as the normal birth-weight is 

 approached. 



The absolute weight of the empty intestines, however, in the test rats of Group I 

 and II is below that of the prenatal controls, 3 and 5 per cent, respectively. In 

 Group III in the test rats it is 27 per cent above, and in Groups IV and V it is 12 and 

 16 per cent respectively below that of the controls ; averaging 2 per cent below in the 

 test rats for all groups. This difference in absolute weight is slight and may be due 

 to the difficulty of removing the intestinal contents in a uniform manner. It is 

 difficult to explain on any other premises why the absolute weight of the intestines 

 with contents in the test rats should exceed that of the controls by 15 per cent while 

 below them 2 per cent in absolute weight when empty. Jackson (1915a), however, 



