PHYSIOLOGICAL STUDIES OF THE CHINOOK SALMON. 445 



REFERENCES. 



Ri'ttkk, Cloudsley. Studios mi the natural history of the Sacramento Salmon. Popular Science 



Monthly, July, 1902. 



Natural history of the Quinnat Salmon. Bulletin V. S. Fish Commission, XXII, 1904, 65. 



MrESCHER-RuESCH, Friedkicii. Statist isilu- und Biologische Beitr.ige zur Kenntniss vum Leben des 



Rheinlachsea im Siisswasser. Schweizerische Fischerei-Ausstellung zu Berlin, 1880, S. 154. 



Histochemische und Physiologische Arbeiten. Leipzig, 1897. 



Henderson, Yandell. Contrihutions to biology from investigations on the 1 needing salmon. Popular 



Science Monthly, April, 1902. (This paper is a review of Miescher-Ruesch's contributions on the 

 subject, i 

 Paton, D. Noel. Report of investigations on the life history of the salmon in fresh water. Fishery 



Board for Scotland Reports, 1898. 

 Schoenlein, K. Beobachtungen ueber Blutkreislauf und Respiration bei einigen Fischen. Zeitschrift 



fur Biologie, XXXII, 1895, S. 511-547. 

 Brunninos, W. Zur Physiologie des Kreislaufes der Fische. Pfliiger's Archiv fur die gesammte 



Physiologie, Bd. 75, 1899, S. 599. 



II. A STUDY OF THE BLOOD AND SEROUS LIQUIDS BY THE FREEZING-POINT 



METHOD. 



The chinook salmon, spending a greater part of the individual life in the sea, 

 yet beginning that life and ending it in fresh water, would scon to furnish an ideal 

 subject in which to study the osmotic balances which exist between the surrounding 

 media and the living tissues. 



It is known that among marine fishes the sharks and rays" have blood which has 

 a general concentration as regards its physical characteristics about equivalent to 

 that of the surrounding sea water. Further, it has been shown that these Selachii 

 have a certain amount of power of adaptation to varying concentration of the sur- 

 rounding water. The bony fishes, on the other hand, are said to have blood which 

 varies very little from the concentration for mammalia and other higher vertebrates. 

 Even marine bony fishes are supposed to possess this average concentration of the 

 blood,'' a concentration considerably below that of the water in which the animal 

 lives. The salmon, like all anadromous fishes, must either possess the power of 

 adapting itself to or is not susceptible to the change produced by running from fresh 

 water to sea water when young, and to the reverse conditions when it runs up the 

 rivers to the spawning beds, as already mentioned. 



THE BLOOD OF SALMON FROM SALT WATER. 



I collected samples of blood from 18 marine salmon during the month of July, 

 L902, c and measured the concentration of the same by the freezing-point method. 

 The depression of the freezing point is a measure of the total molecular concen- 

 tration, i. c., the concentration due to molecules and ions in solution. The conduc- 

 tivitv was not measured in these experiments, hence I have no check on the 

 proportionate quantity of nondissociated and of dissociated molecules. The rapid 



aRodier, E., Observations et experiences comparatives sur L'eau de mer, le sang et des liquides internes des animaux 

 marins; Travaux des labor, de la Stat. zool. d'Arcachon, 1899, 10S-123. See also < ompt. Kendus, 131, 1900, p. 1008. 



^Griffiths, A. B., Physiology of the Invertebrata, New York, 1892, pp. 140-141. says that the bloodof marine bony fishes 

 does not contain more soluble salts than the blood of fresh-water fishes. Bottazzi, Archives italiennes de Biologie 28, p. 

 61, finds the concentration to lie intermediate between that of the blood of sharks and of air-breathing animals. 



('I have to thank the Sacramento River Packers' Association for the privilege of working at their Monterey wharf and 

 for many courtesies extended. 



B. B. F. 1904—29 



