Effect of Salt Upon the Invertebrate Heart. 25 1 



100 parts NaCl, 7.8 parts MgCU, 3.8 parts MgS04, 2.2 parts KCl, 

 3.25 parts CaCU, all of y^ m. concentration and oxygen. In 

 case the oxygen is added in the form of the peroxide, sodium 

 bicarbonate or sodium hydrate must be added to neutralize the 

 acid introduced with the peroxide. 



8. Sea water to which has been added calcium chloride acts 

 in the same w^ay as does the artificial solution. 



9. The normal circulating fluid oi the crab must contain a larger 

 proportion of calcium than does the sea water. 



10. Lithium chloride can not be substituted for sodium chloride 

 in the artificial solutions. 



