120 C. M. JACKSON AND C. A. STEWART 



The individual viscera. In rats underfed from birth to three, 

 six, or ten weeks, Stewart ('18) found in general a marked rela- 

 tive increase in the weights of the spinal cord, eyeballs, liver, 

 stomach, and intestines (empty). A less marked tendency to 

 increase occurred in the brain (especially in the earliest period), 

 heart (progressive increase), spleen (at six or ten weeks), intes- 

 tinal contents (at six or ten weeks), suprarenals (progressive in- 

 crease), kidneys, testes, epididymides (at three and six weeks, 

 loss later) ovaries and hypophysis. No marked change was 

 found in the weights of the thyroid and pineal gland, but a defi- 

 nite loss of weight occurred in the lungs and especially in the 

 thymus. In the earliest period only (up to three weeks) there 

 was a loss in the weights of spleen and intestinal contents. 



In rats underfed for very long periods (beginning at three 

 weeks of age) , Stewart found the earlier well-marked overweight 

 still evident in the spinal cord, eyeballs, and (usually) the supra- 

 renals. The brain showed a slight increase (above normal), and 

 also the lungs (probably abnormal). There was apparently no 

 marked change (or inconstant variability) in the weights of the 

 intestinal contents, kidneys, ovaries, testes (?), and pineal body. 

 The thyroid, thymus, heart, liver (variable), spleen (variable), ali- 

 mentary canal (empty), epididymides and hypophysis (male) 

 usually became subnormal in weight during the long underfeed- 

 ing periods. 



In rats underfed from birth to three, six, or ten weeks and 

 amply refed to a body weight of 25 to 75 grams, Jackson and 

 Stewart ('19) found considerable variation in the extent of re- 

 covery in weight among the individual viscera. The hypophysis, 

 suprarenals, heart, lungs, and kidneys were usually normal, the 

 liver irregular in weight. The brain, spinal cord, and thymus 

 were almost constantly subnormal, pineal, thyroid, and epididy- 

 mides somewhat irregular. The ovaries were also irregular, ap- 

 parently subnormal in rats refed after underfeeding to ten weeks 

 of age. The stomach and intestines and the eyeballs were usu- 

 ally somewhat above normal weight. The spleen and the testes 

 showed an apparent overweight in the earlier stages, with a sub- 

 normal tendency later. 



