INORGANIC FOODS. 



351 



not know whether the individual organs can effect an exchange of materials, 

 or whether the cells of one group can utilize the waste material of another. 

 The interesting studies of Miescher * on salmon give us some information 

 in this direction. Previous to spawning, these fish migrate from the sea 

 into fresh water, for example, into the Rhine. From the time that these 

 fish reach the river up to the time that the eggs are laid, they take no 

 nourishment. This fact was known to Barfurth 2 and to His. 3 Meischer 

 estimated that the majority of the salmon remained in the Rhine for from 

 six to nine and one-half months, a smaller number stayed up to twelve 

 months, while some were there as long as fifteen months. During all of 

 the time that the fish remains in fresh water, nothing is eaten. The intes- 

 tines are always found empty; and, indeed, Miescher established the fact 

 that the digestive glands during this period do not yield any active juices. 

 A series of marked changes take place in the appearance of the fish during 

 this period. When the salmon first reaches fresh water its organs of regen- 

 eration are quite undeveloped. Being provided with a powerful dorsal 

 musculature, it is able to stem the most rapid currents in the Rhine. On 

 comparing such a fish with one that is taken just before the spawning 

 time, it seems scarcely possible that they are the same kind of fish. 

 The large dorsal muscle has become shrunken; the sexual organs, on 

 the other hand, have become enormously developed. There is a parallel- 

 ism between the two changes. Miescher observed, for example, that the 

 weight of the ovary increased from 9.4 grams to 15 grams, while simul- 

 taneously there was a diminution in the dry substance and in the albumin 

 content of the dorsal muscles as shown by the following average values : 



The albumin lost by the muscles is evidently utilized in building up the 

 sexual glands in one case the eggs, and in the other the sperm cells. 



1 Die histochemischen und physiologischen Arbeiten von Friedrich Miescher, vol. ii. 

 Leipsic, 1897. Pp. 116 et. seq. 



3 TroscheTs Arch. Naturgeschichte, Jg. xli, I, 122 (1875). 



3 Untersuchungen iiber das Ei und die Eientwicklung bei Knochenfischen. Leipsic, 

 1873. 



