[47] BIOLOGY OF THE RHINE SALMON. AG3 
This Homand can only be met by the “liquidation” of muscle- substance 
containing phosphorus. 
* The falling off and the degeneration of the heart of the females de- 
scribed above I have also occasionally noticed in males, but not nearly 
as frequently. The purification of the skin, however, and especially the 
disappearance of the little grains of fat from the muscle of the trunk, 
I have often met with in a more or less advanced stage. One of the fish 
made an exception from the rule (as has been mentioned before), and 
had taken food. Though to a less extent, similar conditions may have 
to be taken into account, as with the females. I am inclined to lay con- 
siderable weight, as regards the improvement of the respiration of the 
tissue, on the reaction and consequent decrease in the consumption 
of oxygen and substance, which certainly follows the strong excitement 
of the spawning period.* The low temperature of the months of De- 
cember and January, following close upon the spawning period, may 
also do its share of the work. It may safely be asserted, moreover, 
that when the season of extraordinary excitement is over, the blood- 
vessels of these lean fish have to supply only about two-thirds or even 
only one-half the original quantity of muscle, and that the demand and 
supply of oxygen have become nearly equalized. 
The proof of the “liquidation” of organs and the description of the con- 
ditions under which this process takes place, which have been furnished 
by the investigations relative to the Rhine salmon, will, I think, very 
soon bear fruit on a more extended physiological and pathological field. 
Many interesting facts are scattered all through the literature of the sal- 
mon, but they were disjointed, and there seemed to be no proper connec- 
tion between them, because the important element of “liquidation” was 
wanting; and because whenever there was a question of the dissolution 
of dead elements of tissue, the positive loss of matter by an organ was 
erroneously considered identical with a change of matter. I will here 
only remind the reader of the intensification of the disintegration of 
albumen by phosphorus, as shown by J. Bauer,t which fact has been 
corroborated by the investigations of O. Frankel.t Bauer attempts an 
explanation by speaking in a somewhat vague manner of ‘an equilibrium 
between organs and juices.” Frankel quotes an attempt at an explana- 
tion.by L. Traube, which very correctly lays stress on the difference in 
*An observation made by Mr. Glaser, about 15 years ago, shows how high the passions 
of these fish run during the spawning period. He had placed a trap containing a 
male fish in the Rhine, directly above Basel, near to a spawning female salmon. A 
male salmon of medium size, prompted by jealousy, made violent attacks on the fish 
in the trap, and was caught, the iron prongs piercing his body. But as the trap was 
old and did not work very well, he succeeded in getting loose. He returned three 
times, however, and tore himself loose as many times, until a new trap was set, in 
which he was finally caught, his whole body being torn and bleeding from twenty 
wounds. 
t Zeitschrift fiir Biologie, vii, viii. 
t Virchow’s Archiv., xvii. 
