Inorganic Ions 



87 



protein content of blood decreases greatly. "*'^ The various ions increase, but 

 in different proportions; usually Na"'" and Cl~ increase more than K *^, and 

 all these more than Ca+ + . When marine animals such as Mesiciotefl ^^ and 

 Carciniis'^''- ^^'* are transferred to dilute sea water, reverse reactions occur, 

 and the blood constituents are diluted in different proportions. These changes 

 occur rapidly during the first few hours and then more slowly, equilibrium 

 usually being reached in 2 to 7 days. A relatively constant body weight is 

 maintained. The net result is that the ratios among the different ions change 



Fig. 24. Concentrations of sodium, potassium, calcium, and of total protein (PR) in 

 the blood of Carcinus as a function of the concentration of the medium (dilute sea 

 water) in freezing point (Ao). From Drilhon-Courtois." 



with a change in total tonicity. Blood proteins decline with increase in blood 



salts (Fig. 24). 



Changes in blood chloride have been followed m numerous species. In 

 dilute sea water the blood chloride concentration decreases, but some regula- 

 tion occurs, and below a certain concentration the blood chloride remains 

 nearly constant (Mesidotea, Fig. 23). In Gamviarns, correspondence of blood 

 chloride to chloride in the medium occurs in higher concentrations, and regu- 

 lation to a constant blood chloride occurs in very dilute media (Fig. 25). 



