PHYSIOLOGY AND EXPERIMENTAL PATHOLOGY 125 



the percentage weight of the corresponding gland in controls except in the 

 case of the gonads. The ovaries and testes were larger in those animals 

 fed suprarenal than they were in the controls. The observations on the 

 testis were more conclusive because that series was larger. 



This effect on the gonads must be largely due to the cortical portion 

 of the suprarenal because very little of the epinephrin contained in the 

 medulla is absorbed through the alimentary canal. 



The amount of suprarenal tissue appears to be a factor in the de- 

 termination of the number of offspring in a litter. Hoskins(c) has found 

 that from a series of guinea pigs with one suprarenal removed, the number 

 of offspring in the course of a year is notably below normal, although the 

 animals appeared to be perfectly like their controls in development and be- 

 havior. 



It is well known that the suprarenal hypertrophies in the mother 

 during pregnancy. The mammalian method of gestation is probably 

 responsible for this enlargement (Elliott and Tucket) because mere pro- 

 ductive activity in itself does not appear to be responsible, for in the fowl, 

 where the reproductive function is prolonged, there is no progressive de- 

 velopment of the suprarenal glands. The placental circulation of the 

 fetus may draw upon the maternal suprarenals for a cat near full term 

 dies more speedily after excision of these glands than at other times (El- 

 liott and Tuckett). 



The work of Watrin(&), however, indicates that suprarenal hyper- 

 trophy during pregnancy is due to the presence of the placenta rather than 

 to the fetus. At about the tenth day of gestation in the rabbit he re- 

 moved the embryo through a small incision in the uterine wall. The 

 wound healed and the placenta continued to develop. The hypertrophy 

 of the suprarenals appeared to become as great as in normal gestation. 



After birth if the young are permitted to take milk from the mother, 

 the suprarenals of the latter continue to increase up to a certain period. 

 On the other hand Verdozzi(a) has found that if, following birth, the 

 guinea pig was hindered from suckling its young, the weight of the supra- 

 renals, which at the moment of birth was generally higher than the normal 

 weight, diminished rapidly and descended below the average normal 

 figure. If the mother was permitted to suckle her young, the weight 

 of the suprarenals increased rapidly, attaining the maximum at the end 

 of about fifteen days. In the latter case the cortex hypertrophied, especial- 

 ly the fasciculated and reticulated zones, the lipoid and pigment increas- 

 ing. 



During the development of the individual there is an increase in the 

 size of the suprarenals particularly the cortex, out of proportion to the 

 increase in body weight (Elliott and Tuckett). 



These observations lead us to believe that the suprarenals bear an 

 important relation to growth and .development. 



