EFFECTS OF INANITION IN THE PREGNANT ALBINO RAT. 97 



GENERAL EFFECTS OF UNDERFEEDING. 

 BLIGHTING OF OVUM. 



In one experiment 17 female albino rats were underfed for varying periods of 

 16 to 26 days from the time of observed copulation. Only 1 (A 6) gave birth to a 

 litter after 24 days. This mother received daily 10 grams of food until the eleventh 

 day after copulation, and thereafter 1 gram daily until delivery, starvation being 

 severe only in the last halt of pregnancy. Her fetuses were autopsicd and included 

 with the data. Of the 17 rats, 4 died of starvation. Autopsy revealed no pneu- 

 monia or other disease. 



In another series 59 females were underfed from the eleventh day after copula- 

 tion to delivery, death, or the discovery of no existing pregnancy. Of this number, 

 19 (table 1), or 32 per cent, gave birth to litters; 12, or 20 per cent, died during 

 pregnancy (table 2) ; and 27, or 46 per cent, did not give birth to litters (table 3) . 



Huber (1915) found that in the rat, on the sixth day after copulation, localized 

 thickenings ot the uterine mucosa, sufficient to cause localized swellings of the 

 uterine tube, were evident. Stotsenburg (1915) has shown that on the thirteenth 

 day of pregnancy the average weight of the rat fetus is 0.040 gram. It is inter- 

 esting to note that in my pregnant rats it was found that the swellings in the uterine 

 horns could be palpated through the abdominal wall of the living animal between 

 the tenth and eleventh days after copulation. None of the females (16 in number) 

 underfed from the time of copulation, and not having litters, showed swellings in the 

 uterine horns at any time palpable through the abdominal wall. In the 27 females 

 (table 3) observed to copulate and underfed from the eleventh day thereafter (no 

 litters resulting), swellings in the uterine horns were palpated in 15 cases, doubtful 

 in 3, and not palpable in 9. Of the 27 animals, 5 died during the starvation period; 

 4 of these were autopsied, 1 (A 63) showing definite swellings in the uterine horns 

 (2 in right, 3 in left, about 8 mm. in diameter), the other three showing no macro- 

 scopic evidence of pregnancy. 



[Microscopic examination of sections of the uterine swellings (in A 63) revealed 

 a mass of degenerating tissue with no evidence of any fetus. One female (B 64) was 

 refed 10 days (after being underfed 12 days) and killed. At autopsy 4 swellings in 

 the left and 5 in the right uterine horn were found, averaging about 1 cm. in diameter. 

 Microscopic examination of these showed a mass of degenerating tissue with no 

 evidences of any fetal tissue. Apparently these were cases of blighted ova or early 

 embryos. What was the fate of the swelling palpated in the other rats starved? 

 Were they absorbed? This question needs further investigation. 



It is significant to note that of the 17 females starved from the time of copu- 

 lation, only one became visibly pregnant and no swellings were ever palpated in the 

 remaining 16. Does starvation early in pregnancy inhibit implantation by lessen- 

 ing the amount of pabulum or embryotroph necessary to the nourishment of the 

 ovum, or by uterine circulatory changes or a condition of acidosis? Or does it 

 cause a blighting of the ovum after implantation? This also needs further inves- 

 tigation. 



