450 ANIMAL PHYSIOLOGY, 
room for individual judgment and the assimilation of such 
ideas as they may suggest outside of the subject in hand. 
The subject of diet is a very large one; but it will be evi- 
dent on reflection that, before an average diet can be prescribed 
on any scientific grounds, the composition of the body and 
the nature of those processes on which nutrition generally 
depends must be known. Nota little may be learned by an 
examination of the behavior of the body in the absence of all 
_ diet, when it may be said to feed on itself, one tissue sup- 
plying another. All starving animals are in the nature of the 
case carnivorous. 
Composition of the Mammalian Body. 
Adult man. New-born child. 
SkeletOnwiicsmasisguiavircdens et. wed aisigawlos 15:9 17-7 
Muscles. we. acnpituanadaandanatesadad Deas agus 41:8 22:9 
Thoracie VISCela.wcsiuawiieeierteds seacres ies 17 3-0 
ee dpumnal VISCETA. cs sckns Rae nearineaers antes 3 11:5 
Ahigneerwrerdaeaer Es LeRERteweNsioae we Ese 18-2 : 
ES RAC AMIS COE SROH OR SHTONID, Ca 69 | ang 
Brain. vag ccanvcansormmosencereumeads as 1-9 158 
For the cat an analysis has yielded the following: 
Muscle and tendons............eeeeeeeee 45°0 per cent. 
BOneS isis tedeare serene. pease onaoncnn etna 47 
SIEM sare esieene caoinakio ne acieaen sat »» 12°0 ie 
Mesentery and adipose tissue..........6+ 38 OM 
Thiver vawstatwertis cieaed neatae ee eat ia 48 “ 
Blood (escaping at death)............... 60 80 
Other organs and tissues................ By Of 
The large proportional weight of the muscles, the similarly 
large amount of blood they receive; which is striking in the 
case of the liver, also suggest that the metabolism of these 
structures is very active, and we should expect that they 
would lose greatly during a starvation period. It is a matter 
of common observation that animals do lose weight and grow 
thin under such circumstances, which means that they must 
lose in the muscles and the adipose tissue. Attempts have been 
made to determine exactly the extent to which the various 
tissues do suffer during complete abstinence from food, and 
this may be gathered from the table given below. 
Starvation —A cat weighing 2,464 grammes lost before death 
on the eighteenth day 1,197 grammes in weight. Of this about 
