342 E. R. HOSKINS 



4. Thyroid feeding (in sub-toxic doses) causes little or no 

 change in body weight in growing rats. There is possibly a 

 slight stimulation in growth of the body as a whole, balanced 

 by a decrease in the amount of free fat in the body. There 

 is a slight loss in the relative weights of the eviscerated body and 

 the integument, probably due to loss of body-fat. 



5. Thyroid feeding produces a decided hypertrophy of the 

 heart, liver, spleen, kidneys and suprarenal glands (especially 

 in males). It apparently causes also a somewhat less exten- 

 sive and more uncertain increase in the weights of the alimen- 

 tary canal and hypophysis (male) and possibly in the skeleton, 

 testes and epididymi, and a decrease in the weight of the 

 hypophysis of females. 



6. Thymus feeding (with the dosage employed) has no ap- 

 parent effect upon the growth rate of the body of albino rats. 

 No constant or important effect upon any of the individual 

 organs or parts was observed. The testis showed no degenera- 

 tive or other changes. 



7. Hypophysis feeding (with the sub-toxic dosage employed) 

 produces no marked or constant effect upon the growth rate of 

 the body or organs of albino rats. 



8. Pineal feeding likewise produces no apparent changes in 

 the weight of the body or organs of the albino rat, beyond dif- 

 ferences probably within the limits of normal variation. 



