74 RELATIVE SIZE OF THE HEART. 



Com2)arative Weights of the Hearts of Rejdiles. 









Proportion to weiglit 









of entire animal. 



Weight of the 



heart 



of Jlaiia catcshccana (Biillfi'ojj) .... 



1 



5 7 6 





Heterodon niger (Black Viper) .... 



1 



4 9 6 



(( 



II 



Coluber constrictor (Black Snake) 



J 



5 2 f 



<( 

 It 



It 

 It 



Coluber gidtatus (Corn Snake) .... 

 Psammoplds jlctgelUformis (Coacliwhip Snake) . 



1 



4 0 0 

 1 



'Sst 



n 



II 



Crotalus durissus (Rattlesnake) .... 



1 



44 T 



It 



II 



Chelonura serpentina (Snappinii; Turtle) 



1 



4 03 



It 



II 



Glielonia caretta (Loggerhead Turtle) . 



1 



4 8 0 



tl 



II 



Emys reticulata (Chicken Terrapin) 



* 4'25r 



11 



tl 



Emys serrata (Yellow-bellied Terrapin) 



1 



S 9 2 



It 



II 



Emys serrata (Yellow-bellied Terrapin) 



1 



5 17 



It 



II 



Emys serrata (Yellow-bellied Terrapin) 



1 



5 4T 



11 



II 



male Testudo polyphemus (Gopher) 



4 5T 



II 



11 



male Testudo polypliemus (Gopher) 



1 



4 7 0 



II 



II 



female Alligator Mississippiensis (Alligator) 



1 



3 9 8 



Comparative Weights of the Hearts of Birds. 



Proportion to weiglit 

 of entire animal. 



Weight of the heart of Meleagris gallopavo (Wild Turkey) % 

 " " 3Ieleagris gallopavo (Wild Turkey) 



" " Syr7iium nebulosuni (Barred Owl) 



" " Cathartes atratus (Turkey-buzzard) 



" " Tantalus loculator (W ood Ibis) . 



" . " Tantalus locidator (Wood Ibis) . 



2 7 9 



I 



2TS" 

 _] 

 2 2 0 

 _ 1 

 iTj 

 _ 1_ 



1 0 8 



Too' 



Comjxiraiive Weights of the Hearts of Mammals. 



Proportion to weiglit 

 of entire animal. 



Weight of the heart of Common Sheep 



" " Sciurus Carolinensis (Gray Squirrel) 



" " Didelphis Virginianus (Opossum) 



" " Common Cat 



" " Procyon lotor (Raccoon) 



" " Procyon lotor (Raccoon) 



" " young Procyon lotor (Raccoon) 



" " Pointer Dog 



By comparing these tables, we see that the heart is proportionally smallest in 

 Fishes and largest in Birds. 



As the organs and apparatus of the animal economy are developed and per- 

 fected, the circulation of the nutritive materials becomes more vigorous. 



As the temperature, intelligence, and activity of animals, with their correspond- 

 ing physical and chemical metamorphoses of the elements of organic structure 

 increase, there is a correspondingly rapid supply of those materials by which the 

 wastes may be repaired, and from which the various secretions and excretions 

 may be elaborated and separated. 



The next consideration is the rapidity of the circulation in different animals. 



2 5 C 

 _ 1 

 2fi I 



_1 _ 



2 '3 0 

 _ 1. 



2 7 5 



_1 _ 



] '6 4 



TTo 



_i_ 



1 4 2 



