gg EFFECTS OF INANITION IN THE PREGNANT ALBINO RAT. 



LENGTH OF GESTATION. 



According to Stotsenburg (1914), the length of gestation in the non-lactating 

 albino rat varies from 21 days and 15 hours to 22 days and 16 hours. The length 

 of gestation in my starved mothers varied from 21 to 26 days; 8 of the 22 total are 

 above the 23-day limit— 6 with a gestation-period of 24 days, 1 of 29, 1 of 26. Thus, 

 severe inanition during the last half of pregnancy usually lengthens the duration 

 of gestation comparatively little. This is rather surprising, in view of the fact 

 that King (1913) found the gestation period markedly lengthened in pregnant 

 nursing rats. King says: 



"The period of gestation is always prolonged when a female is suckling six or more 

 voung In these cases the number of young in the second litter seems to have less influ- 

 ence on the length of the gestation period than has the number of young suckled, but if 

 both litters are very large, the gestation period may be extended to 34 days." 



Daniel (1910) in investigations on the mouse, formulated the following law 

 (quoted by King, 1913, as 'Daniel's law'): "The period of gestation, in lactating 

 mothers, varies directly with the number of young suckled." 



Both Daniel and King seem to have overlooked the work on the prolongation 

 of gestation in different species of rats by Lataste (1891), in which he states: 



"On voit que, d'une facon generate et sauf perturbations accidentelles, le retard de 

 la gestation, dans'une meme espece, est proportionnel au nombre des petits allaites, un 

 nouveau join de retard correspondant a un nourisson de plus." 



He proved that the retardation of gestation was due to a delay of the implan- 

 tation of the ovum during the first 6 to 10 days of pregnancy, due probably to a 

 lack of proper nourishment for the ovum as it enters the uterine cavity. He found 

 that traumatizing the mother early in pregnancy markedly prolonged gestation, 

 while at later periods there was no effect. This is in harmony with my observation 

 that there is very little prolongation of gestation in starvation during the latter 

 half of pregnancy. ^^ ^ pREMATURE DELIVERY . 



Although my females were kept in cages with meshed-wire bottoms, so that the 

 products of conception might fall through, no abortions or premature deliveries 

 were observed. Rudolski (1893), in inanition experiments on rabbits and a dog, 

 stated that premature deliveries seldom occurred, and that abortions were never 

 observed Prochownick (1901) cites 48 cases in which women were placed on a 

 restricted diet during the last halt of pregnancy, with no abortions or premature 

 deliveries resulting. He also reviewed the earlier literature upon the subject. 

 Paton (1903) observed no abortions or premature deliveries in guinea-pigs starved 

 during pregnancy. Reeb (1905) observed premature deliveries in 2 rabbits 

 starved from the beginning of pregnancy, but none in rabbits or dogs starved 

 during the last halt of pregnancy. 



Although no abortions or premature deliveries were observed, it is interesting 

 to note that 5 of the 12 females that died during pregnancy (table 2) began to bleed 

 from the vagina 1 to 3 days before the end of the normal gestation period. In one 



