310 



THE BLOOD 



TABLE XLI 

 Non-clotting Plasma 



Similarly, certain snake venoms which contain large quantities of 

 thrombin cause clotting of the blood in the vessels and rapid death. 



Components, (ii.) Crystalloids. 



There is nothing more remarkable than the maintenance of 

 a fairly constant concentration of crystalloids in plasma, under 

 the most varied conditions. As we have seen, this is due in great 

 part to the salt- and water-holding power of the colloidal con- 

 stituents, especially of the globulins. Bungc, in his handbook of 

 physiological and pathological chemistry (1889), suggested that 

 as the notochord and branchial clefts were legacies from fore- 

 bears who had lived in the sea, the high sodium chloride content 

 of mannualian blood might also be an heirloom from marine 

 ancestors. No doubt the circulation fluid of marine animals 

 with an open coelomic system is sea water. It is held by many 

 observers, that when the ancestral form of vertebrates acquired 

 a closed form of circulatory system, the fluid shut in was sea water. 

 Analysis shows that while the concentrations of crystalloids in 



