EFFECTS OF INANITION IN THE PREGNANT ALBINO RAT. 99 



of these (B 64), the fetuses had evidently been dead for some time, as upon section 

 and microscopic examination of the swellings in the uterine horns, a degenerating 

 mass of material was found, in which no fetal structures were distinguishable. 

 Rat B 58 (table 2), killed after refeeding 10 days, showed a similar condition in the 

 uterine horns ; but the death of the fetuses evidently occurred earlier, as the swellings 

 of the uterine horns were smaller (5 to 8 mm. in diameter, as compared to 9 to 15 

 mm. diameter in B 64) . 



Macroscopic examination of the placentas of the rats dying after hemorrhage 

 revealed no separation of the placentae and no evidence of beginning labor. Are 

 these cases to be regarded as beginning abortions in which the fetuses have died 

 in utero and therefore analogous to missed abortions occurring in the human? 

 This subject requires further investigation, checked up by careful microscopic 

 examination to determine whether this bleeding is due to a beginning abortion or is 

 the result of degenerative changes in the placenta itself, or perhaps due to changes 

 in the maternal blood. 



STERILITY. 



From the total number of 76 females starved during pregnancy (or suspected 

 pregnancy), only 4 became pregnant a second time (B 2, B 29, B 43, and B 44, 

 tables 1,2, and 3) . Of the 76 starved, 21 died, a mortality of 27 per cent. Although 

 the remaining 55 were placed with the males frequently, only 4, or 7 per cent, 

 became pregnant after starvation. Thus it appears that inanition during preg- 

 nancy produces a condition of sterility in the majority of the females. Whether 

 this sterility is absolute or only temporary can not be as yet stated, since a sufficient 

 period has not elapsed since the starvation of many of the females. 



Jackson and Stewart (1919) likewise found that starvation in young female rats 

 produced sterility in a large number of cases. 



STILLBIRTHS AND VIABILITY OF THE NEWBORN. 



From the data in table 1, it is seen that from a total of 129 newborn youno- 

 from mothers starved during pregnancy, 41 were found dead after delivery. 

 Whether these were dead in utero, died during delivery, or afterwards, it is impos- 

 sible to state. At birth, the newborn dropped through the wire bottom of the cage, 

 and as many were born inclosed within the amniotic sac, death may have resulted 

 from suffocation. The living seemed to be quite vigorous. As they were autop- 

 sied as soon as possible after birth, no statements can be made concerning the via- 

 bility and after-life of these newborn. King (1916), however, has made a study of 

 the growth of albino rats undersized at birth (one a female weighing but 2.6 

 grams). She states: 



"A very small weight at birth indicates that a rat has a handicap in its organization, 

 that environment, however favorable, can not overcome. Such animals, although they 

 appear vigorous and healthy during their growth period and after reaching the adult state, 

 are unquestionably subnormal in regard to the size of the body and the central nervous 

 system." 





