WEIGHTS OF ORGANS IN UNDERFED YOUNG RATS 



139 



LIVER 



The liver (table 17) in the albino rats held at constant body- 

 weight from the age of three weeks to six, eight and ten weeks 

 shows an apparent increase. This increase appears greatest 

 in the shortest series, three to six weeks, increasing from 4.95 

 per cent of the body-weight (in controls) to 5.89 per cent. Be- 

 tween three and ten weeks the corresponding increase is from an 

 absolute weight of 1.16 grams (1.20 grams, less correction for 

 difference in body-weight; or 4.95 per cent of the body-\Veight) 

 to 1.28 grams (5.25 per cent of the body-weight), or an increase 

 of about 10.3 per cent in absolute weight. 



In the later and longer periods, however, there appears to be 

 a decided decrease in the weight of the liver (six to thirty-two 

 weeks and ten to thirty-five weeks series). This may be due to 

 the fact that the latter experiments extended over a longer period 

 of time, or it may be because they were begun at a later age. 

 We may therefore conclude that in young albino rats held at 

 constant body-weight there is, beginning at three weeks, an 

 increase in the weight of the liver (apparently greater at six than 

 at ten weeks of age) ; while in rats beginning the experiment later, 

 at six and ten w^eeks of age (and extending over a longer period) 



TABLE 17 



The liver; average absolute weight, average percentage of net body-weight and range 



indicated 



DESCRIPTION OF RATS 



Normal at 3 weeks (Jackson '13) 



Controls at 3 weeks 



Body-weight constant 3 weeks (age of 3 to 6 weeks) 

 Body-weight constant 5 weeks (age of 3 to 8 weeks) 

 Body-weight constant 7 weeks (age of 3 to 10 weeks) 



Normal at 6 weeks (Jackson '13) 



Control at 6 weeks 



Body-weight constant 26 weeks (age of 6 to 32 weeks) 



Normal at 10 weeks (Jackson '13) 



Controls at 10 weeks 



Body-weight constant 25 weeks (age of 10 to 35 weeks) 

 Controls at 32 and 35 weeks 



.ABSOLUTE WEIGHT 



(.AND range; : gr.^^ms 



relative weight 

 (and range) : 



PER CENT 



0.87 (0 

 1.20 (1 

 1.30 (0 

 0.92 (0 

 1.28 (0 

 3.19 (2 

 2.18 

 2.33 (2 

 4.50 

 6.72 (4. 

 3.11 (2 

 7.27 (5 



42-2.08) 

 06-1.38) 

 89-1.63) 

 78-1.06) 

 80-1.82) 

 18-4.76) 



21-2.45) 



91-8.66) 

 30-3.51) 

 84-9. 86) 



4.50 (3.21-5.82) 



4.95 (4.03-6.00) 



5.89 (4.32-7.39) 



5.12 (4.36-5.88) 



5.25 (3.63-7.00) 



6.48 (5.39-8.46) 



5.13 



4.44 



6.00 



4.99 (4.28-5.72) 



4.25 (3.91-4.74) 



3.84 (3.47-4.14) 



