CHAP, v.] NUTRITION. 825 



In all cases the loss during starvation falls most heavily upon the 

 adipose tissue ; this tissue is the first to waste, and in time nearly 

 the whole of it disappears. This we might expect from our know- 

 ledge that the fat of adipose tissue is a store of superfluous 

 material. In all cases the skeletal muscles undergo a great loss, 

 and their wasting contributes largely to the loss of weight of the 

 whole body; this confirms what we already know concerning the 

 active metabolism of this tissue and the large share which it 

 takes in the total metabolism of the body. We may here remark 

 that the loss suffered, in such cases, by the muscles appears to be 

 a loss of the whole substance of the muscle, a diminution in total 

 bulk, not a withdrawal of any particular constituent. In the 

 particular case of the cat quoted above the losses undergone by 

 the liver and spleen are very great indeed, relatively greater than 

 that of the skeletal muscles ; though this result is consistent with 

 what we know of the metabolic activity of these organs, the loss 

 recorded in other observations is not nearly so striking. The 

 several observations do not agree as to the loss sustained by the 

 bones ; in some cases these lost a large amount of solid matter, in 

 others the loss was chiefly that of water. 



In all cases the blood while diminishing in bulk remains other- 

 wise about the same ; in starvation as in ordinary circumstances 

 the several tissues struggle to keep the blood in an average con- 

 dition. Very striking is the fact that though the skeletal muscles 

 suffer so heavily, the muscles of the heart sustain hardly any loss ; 

 on account of its importance to the whole body, the heart is kept 

 supplied with material, it feeds on the rest of the body. The 

 same remark applies to the brain and spinal cord ; in order 

 that life may be prolonged as much as possible these important 

 organs are nourished by material drawn from less noble organs 

 and tissues. 



In many of the observations on starving animals quantitative 

 determinations of the excreta during the starvation period have 

 been made with the view of inferring the nature and extent of the 

 metabolism going on. And the same has been done in the case of 

 men fasting (that is to say, abstaining from solid food, but drinking 

 water, and in some cases taking drugs) for periods varying from 

 six to thirty days. 



During the starvation period there is a daily output of nitrogen 

 in the urine ; this serves as a measure of proteid metabolism. 

 The main source of this nitrogen is shewn by the case of the 

 above-mentioned cat. In this case during the starvation period, 

 the urine contained in the form of urea (and that practically 

 represents all the nitrogen of the urine) 27 '7 grammes of nitrogen. 

 Now the amount of muscle which was lost during the period con- 

 tained about 15'2 grammes of nitrogen. Thus, at least, more than 

 half the nitrogen of the output during the starvation period must 

 have come ultimately from the metabolism of muscular tissue. 



F. n. 53 



