of the Salmon in Fresh Water. 175 



possibly out of the very widely distributed yellow pigment. Its storage 

 in the muscles and its transference to the ovaries has been demonstrated. 

 Its fate in the male fish is still obscure, though the deeper pigmentation 

 of the skin in the male suggests its elimination by that channel. What 

 the purpose of the pigment is, is not clearly indicated, though it seems 

 probable that by colouring the ova it may assist in their concealment 

 during development. 



VIII. Nature of the Transference of Material. 



On the nature of the transference of material these observations also 

 throw important light. They clearly show that nothing of the nature 

 of a degeneration in the muscle take place. The muscles simply excrete 

 or give out the material accumulated in them. 



Miescher discusses this point at great length. He first considers if 

 what he calls the liquidation and degeneration (Fettentartung) 

 is caused by changes in the nerves. But since he finds no visible 

 changes in the nerve bundles to the muscles he dismisses this possibility. 

 According to his view, the liquidation is caused by deficient respiration 

 in the muscle, due to the deficient supply of blood as a result of the 

 starvation and of the rapidly growing ovaries taking off a Larger and 

 larger amount of blood from the muscles. He supports this view first 

 011 general physiological principles, and secondly, from a consideration of 

 the blood supply to the muscles and ovaries at various periods. 



The theory, however, assumes that the change in the muscle is a 

 degeneration, which it is not, and it affords at best but a partial 

 explanation of the condition. It is too mechanical, and leaves unsolved 

 the problem of what starts the growth of the ovaries, what causes the 

 dilatation of blood-vessels there, and thus leads to the diminished blood 

 supply to the muscles. The growth of the ovaries may be considered a 

 cyclic function, but in all these cyclic functions the nervous system is 

 intimately involved. It is well known that not only is the blood supply to 

 every part of the body under the control of the nervous system, but that 

 the very rate of chemical change in the cells of the body is also under 

 the influence of the nerves. Not only does the brain bring about and 

 control the extensive chemical changes in the muscles which lead to 

 movements, but it also governs the slower chemical changes, such as 

 those by which heat is produced in the warm-blooded animals. The 

 building up and breaking down processes are alike controlled by nerves, 

 and it is only fair to assume that the growth of the ovaries and testes 

 and the discharge of material from the muscle for their growth are primarily 

 determined by the nervous system, and that the vascular changes are 

 secondary and not causal. In this connection it must be remem- 

 bered that throughout the whole period the muscles remain active, and 

 not only excrete material to the ovaries and testes, but also set free the 

 energy of the proteids and fats stored within them, a state of matters 

 irreconcilable with the idea of the existence of a degenerative process. 



The investigation of kelts, though limited in extent, seems to show 

 that, from the period of spawning to the return to the sea, the expen- 

 diture of energy is at a minimun. That many ova remain unshed in 

 the abdomen is clearly shown, and that these ova are absorbed and 

 shrivel up has also been proved. It is thus highly probable that, as 

 indicated by Miescher-Ruesch, the kelt utilises its unshed spawn. 

 We have discovered no evidence that kelts feed. In none of the 

 22 fish examined was there any trace of food in the stomach, or 

 any remains of food in the intestine. On the other hand, a point of 

 very great interest is the regeneration of the lining membrane of the 

 stomach and intestine, and the reappearance of bile in the gall bladder, 



