THE EFFECTS OF INANITION IN THE PREGNANT ALBINO HAT. WITH 

 SPECIAL REFERENCE TO THE CHANGES IN THE RELATIVE 

 WEIGHTS OF THE VARIOUS PARTS, SYSTEMS, AND 

 ORGANS OF THE OFFSPRING. 



By Lee Willis Barry, M. D., Ph. D. 



That a restriction of the diet of the mother during pregnancy usually results 

 in a decrease in the weight of the offspring has long been known. Prochownick 

 (1899, 1901) obtained a marked reduction in the weight of the human newborn by a 

 restriction of the mother's diet during the last weeks of pregnancy. Rudolski 

 (1893) starved rabbits and a dog during pregnancy and noted a reduction in the size 

 of the offspring. Paton (1903) underfed pregnant guinea-pigs and obtained a 

 marked reduction in the weight ot the young. Reeb (1905) underfed rabbits and 

 dogs during pregnancy and obtained young greatly reduced in weight. However, 

 none of the above made any observations upon the changes in the relative weights 

 of the various organs, systems, and parts of the newborn which might occur during 

 inanition of the pregnant mother. The main object of this investigation, therefore, 

 is to show the effect of inanition in the pregnant albino rat upon the changes in the 

 relative weights of the various systems, organs, and parts of her newborn. Observa- 

 tions were made also on the possibility of blighting of the ovum, death of the fetus 

 in utero, prolongation of gestation, abortions, and premature deliveries during 

 inanition of the mother. 



The work was done in the Departments of Obstetrics and of Anatomy of the 

 University of Minnesota, under the supervision of Doctors J. C Litzenberg and 

 C. M. Jackson, to whom I am deeply indebted for valuable aid and suggestions. 



MATERIALS AND METHODS. 



For the present investigations, two series of adult female rats (Mus norvegicus 

 albinus) were used for inanition during pregnancy. Those in series A are adult 

 females from the colony at the Institute of Anatomy, which were kindly given over 

 to my use by Dr. C. M. Jackson; Series B consists of adult females from several 

 sources. A few were reared from normal litters in Series A; some were purchased 

 from a local animal dealer, and others were obtained from the departments of 

 Physiology and Psychology of the University. Unfortunately, however, the exact 

 age of very few of the females was known. 



BREEDING. 



Since the influence of inanition on the length of gestation was to be noted, and 

 in order to exclude the possibility of some of the small rats being the result of pre- 

 mature birth, it was very important to know the approximate date of copulation. 



Three methods were used: (1) Kirkham and Burr (1913) have shown that 

 the female albino rat usually ovulates within 20 to 48 hours after the birth of a litter, 

 and impregnation occurs 1 to 4 days after the casting of a litter. A few of my 

 females became pregnant by this method, the males being left with the mother 



93 



