32 



EFFECTS OF GASES UPON THE BLOOD. 



Fig. 3. Fig. 4. 



Fig. 3. — Blood-corpuscles of Salt-water Terrapin {Emys terrapin) in their normal condition. Mag. 210 diameters. 

 Fig. 4. — Blood-corpuscles of Salt-water Terrapin [Emys terrapin) acted upon by a drop of acetic acid, showing the 



nuclei, nucleoli, dumb-bell or hour-glass corpuscles, and beyond, where the acid has not extended, the 



normal corpuscles. Mag. 210 diameters. 



Liquor potassa dissolves the cell-walls, nuclei, and nucleoli, alters the color of 

 the blood to a brownish-yellow, and renders it viscid and ropy, like thick mucus. 

 When treated with aqua ammonia, the corpuscles are at first altered in shape, 

 sometimes elongated ; and, in many cases, the cell-walls began to swell first toward 

 the periphery, as in the action of acetic acid. In a short time, aqua ammonia, like 

 liquor potassa, completely dissolves the corpuscles. 



The colorless corpuscles are more numerous in cold than in warm-blooded animals. 

 Amongst Chelonians, they are most numerous in the Salt-water Terrapins {Emys 

 terrapin). In the blood of these Chelonians, numerous minute granules also 

 abound. These minute granules increase during a rapid repair of the elements of 

 the body. They were found to be much more numerous in the blood of Yellow- 

 bellied Terrapins [Etnys serrata) which had been deprived of food and drink for 

 several weeks, and then transferred to a tub of water and liberally supplied with 

 vegetable food for thirty to sixty days, than in the blood of those Terrapins which 

 had been deprived of food and drink for several weeks. 



Effects of Gases upon the Blood of Cold-blooded Animals. 

 Carbonic Acid Gas. 



Salt-water Terrapins [Emys terrapin) and Yellow-bellied Terrapins [Emys serrata) 

 were placed in large receivers containing this gas. They took long inspirations 

 and expirations, resembling deep sighs. The noise made by the passage of the 

 gas in and out of their lungs, resembled that often made by human beings dying 

 from narcotic poisoning or congestion of the brain. The breathing of the Terrapins 

 became more and more laborious, and less frequent, occurring at intervals of from 

 ten to thirty minutes, and finally ceased in from ten to twelve hours. 



The blood was of a much darker color thnn when the lungs were supplied with 

 atmospheric air, and resembled much the venous blood of the Mammalia. Upon 

 exposure to the air for a length of time, it became, upon its exterior, of a red 



