486 THE AMERICAN NATURALIST [Vol. XLVII 



Why does the intermittent feeding produce such an in- 

 hibiting effect upon the growth of the body in weight? 

 Before attempting to answer this question it should be 

 recalled that these animals utilize a larger portion of their 

 food in building up their tissues than normally fed sala- 

 manders do, the rate of their growth being likewise about 

 one fifth greater. We also pointed out that the animals 

 remained smaller in size and lighter in weight than the 

 controls. We meet, thus, in the case of the periodically 

 starved salamanders two contrary phenomena: on the 

 one hand, we observed and directly measured on a number 

 of individuals their deficient growth ; on the other hand, 

 we found that the growth activity has not been impaired, 

 but even somewhat greater than in the case of the control 

 Tritons. In the paper, already referred to in the begin- 

 ning of this article, I showed that the water content of 

 the organism increases 4 per cent, when salamanders are 

 returned to a normal diet after protracted starvation. 

 The water content probably comes back to the natural 

 level when the animals have again reached their normal 

 state. In the case of the intermittently fasting sala- 

 manders this may not happen, if the fast is repeated 

 before the effect of the preceding inanition has been 

 overcome. If we recall that the per cent, of water in 

 the organism of starved individuals is also somewhat 

 higher than the usual (by 1.5 per cent.) it becomes quite 

 probable that water may be accumulating in the tissues 

 of intermittently starved specimens to the extent of being 

 a hindrance to their growth. 



Acute hunger has an entirely different effect. It may 

 even exhaust the organism for a time, but so long as de- 

 generation has not set in— degenerative changes appear 

 generally in the advanced stages of starvation — inanition 

 may produce an invigorating influence upon the organ- 

 ism, which has its parallel in the embryonic growth only. 

 The temporary relief which the organs of digestion get 

 may contribute much towards improving their capacity, 

 but the resulting rejuvenation of the organism is a com- 



