GENERAL METABOLISM. 



635 



lessened only in certain directions. On the other hand, in discussing 

 animal oxidations we called attention to the importance of the preliminary 

 cleavage for a complete combustion. 1 



If food is no longer withheld from the animal, it recovers rapidly. 

 It replaces first of all what it has lost of its own body-substance, and seeks 

 to regain its former condition. 



Now it is very interesting to find that during starvation the animal 

 organism attacks the different parts of its own body-material to quite 

 different extents. It might have been expected, a priori, that those organs 

 would suffer most upon which the greatest demands are placed. On the 

 contrary, there is a constant transference of material to those organs which 

 are most useful and are consequently most indispensable to life. This was 

 shown very clearly in considering the life and development of the salmon, 2 

 and led to the question whether we must not assume that the starving 

 organism is obliged to effect extensive syntheses from the building-stones 

 of the less important cells. We can easily believe that the heart, whose 

 function is so essential for the maintenance of life, retains its material 

 unchanged and carries out its work at the expense of other tissue. On 

 the other hand, it is also possible that the muscle-cells of the heart are 

 constantly being broken down and rebuilt. At present we have no means 

 of estimating the life of a cell, and cannot decide how long it can retain its 

 corporate existence, or whether it is constantly assimilating and giving up 

 material. If the latter is the case, then the tissues of the starving organism 

 must be the scene of remarkable transformations. 



Voit 3 gives the following values for the loss of body-weight during starva- 

 tion in the case of doves and cats. 



1 Cf. Lecture XIX, p. 451 et seq. 



2 Cf. Lecture XVI, p. 351. 



3 Handbuch der Physiologic des Gesamtstoffwechsels und der Fortpflanzung. Part I. 

 Physiologic des allgemeinen Stoffwechsels und der Ernahrung by C. von Voit, Vol. 6, 

 p. 96, 97 Leipsic (1881). ' - 



