820 KEPORT— 1897. 



matter of imbibition is in the highest degree improbable, because the cells must be, 

 at the commencement of the experiment, soaked to the highest degree possible in 

 those constituents of the animal's serum which they are capable of taking up. 



Electro-osmotic action is again improbable, because secreting membranes pro- 

 duce ingoing electrical currents as well as absorbing membranes ; and, to apply 

 such an hypothesis, it would be necessary to assume that the ingoing current of the 

 cells is active in one case (absorption), the outgoing retm-n current in the other 

 (secretion) involving the further hypothesis of some valvular nature of protoplasm 

 with higher ' porosity ' in the ' in-out ' direction in the absorbing, and the ' out-in ' 

 direction in the secreting, membrane. 



Finally, any aspirating action of the blood current in the capillaries of the villi 

 is negligible on account of the low velocity of the current in capillary districts of 

 the circulation. 



The Function of the Canal of Stilling in the Vitreous Humour. 

 By Professor Anderson Stuart. 



9. Description of some jneces of Physiological A2)j>aratu3. 

 By Professor Anderson Stuart. 



10. On the PhosplLorus MetahoUsm of the Salmon in Fresh Water. 

 By D. Noel Paton, M.D., F.R.C.P. {Ed.). 



The observations here recorded form part of an extended study on the meta- 

 bolism of the salmon in fresh water. 



The method of investigation was to take for analyses sample salmon through- 

 out the spring, summer, and autumn from tbe mouths of certain rivers, and other 

 specimens from the upper waters of the same rivers, and by comparing these to 

 arrive at conclusions as to the extent of the changes going on. 



Observations made by Drs. GuUand, Gillespie, Uunlop, and myself clearly show 

 that the fish do not feed during their stay in fresh water. The muscle substance 

 steadily diminishes, while the ovaries and testes grow at its expense. The fats 

 and proteids lost from the muscles are sufficient to supply these materials for the 

 growing genitalia, and to yield a very large amount of energy for muscular work. 



The question here discussed is the Exchange of Phosphorus. 



It is first shown that in muscle the phosphorus is chiefly in the form of 

 inorganic phosphates, though a comparatively large amount of lecithin and a small 

 amount of nuclein are also present. 



In the ovary the phosphorus is chiefly combined in the pseudo-nuclein — ichthu- 

 lin ; but it is also present in considerable amounts in lecithin, and in very small 

 amounts as inorganic phosphates. 



In the testis the phosphorus is chiefly in the form of true nucleins, but there are 

 also a considerable quantity of lecithin and a small quantity of inorganic phosphate. 



As the season advances the phosphorus in the genitalia increases, while the 

 phosphorus of the muscle diminishes. The loss of phosphorus from the muscle 

 IS barely sufficient to account for the gain in the ovary, amply sufficient to yield 

 the increase of phosphorus in the testis. The lecithin lost from the muscle is 

 sufficient only to account for a small part of the lecithin gained by the ovary. 

 The lecithin and ichthulin of the ovary must thus be found by synthesis as these 

 structures grow. The nuclein of the testis must be formed in a similar manner. 



The presence of considerable amounts of lecithin in the growing ovary and 

 testis would seem to indicate that this substance is one of the first stages in the- 

 construction of nucleo compounds. 



