THE METABOLISM OF THE BODY. 451 
204 grammes (17 per cent) was in albuminous matter; 132 
grammes (11 per cent) loss of fat ; 863 grammes loss of water, 71 
per cent of the total body weight. 
It will not be forgotten that about three fourths of the 
body is made up of water, so that the loss of so large an 
amount of the latter during starvation is not wholly inexpli- 
cable. 
In the case of another cat during a starvation period of thir- 
teen days 734 grammes of solids were lost, of which 248 grammes 
were fat and 118 muscle—i. e., about one half of the total loss 
was referable to these two tissues alone. 
The other tissues lost as follows, estimated as dry solids: 
Adipose tissue .... 6... see e ee eee eee eee 97°0 per cent, 
ISPS OL wsencinti a wid afarhinahionarerinea rae darteagane 631 
DGD WOD a sat sieass ose 55 iho iu bates seca hea nee 56°6 i 
Muscles <:sixicisisise caeeiie ete R NS alga catia hee ote 30°2 uy 
Blood sis cee ci saseee eres eae weaed se 17°6 - 
Brain and spinal cord... ...........006. oo “ 
It will be observed (a) that the loss of the fatty tissue was 
greatest, nearly all disappearing; (b) that the glandular struct- 
ures were next in order the greatest sufferers; (c) that after 
them come the skeletal muscles. 
Now, it has been already seen that these tissues all engage 
in an active metabolism with the exception of adipose tis- 
sue. 
The small.loss on the part of the heart, which is still less 
for the nervous system, is especially noteworthy. Two ex- 
planations are possible. On the one hand, we may suppose 
that their metabolism is active, but that they feed in some 
sense on the other tissues, and thus preserve themselves from 
loss of substance. But, again, we have seen that the functional 
activity of the nervous system is not accompanied by any very 
marked chemical phenomena that we have succeeded in detect- 
ing, at all events; and little is known of the metabolism of 
the heart itself. Do its pulsations from long habit go on with 
little expenditure of energy, as is the case with the automatic 
workman engaged in a narrow round of duty? Has the nerv- 
ous system in the course of its evolution acquired the power 
of accomplishing much, like persons with special -aptitudes, 
with little loss of energy ? It is not possible to decide exactly 
what share these several factors may take; though that they 
all and others as yet unrecognized do share in the general 
result seems probable. The loss of adipose tissue is so striking 
