60 



SPECIFICITY OF THE BLOOD OF VEETEBRATES 



such., 1868, 391; Physiologische Chemie, 1881, 401) (table 22), varying 

 doubtless in different genera, species, individuals of the same species, etc. 

 In birds, taking the goose as the representative, the percentage is approxi- 

 mately only two-thirds that in mammals, while in cold-blooded animals, as 

 indicated by the snake, the proportion is only about half of that in mammals. 



THE PERCENTAGE OF HEMOGLOBIN IN THE MOIST ERYTHROCYTES IN 



RELATION TO GENERA. 



The percentages of hemoglobin in the moist corpuscles probably vary, 

 according to the records of Abderhalden and others (Schmidt, Character, 

 d. epidem. Cholera, Leipzig, 1850; Gorup-Besanez, Physiologische Chemie, 

 1878, 345; Bunge, Zeit. f. Biologic, 1876, xn, 191; Biernachi, Centralb. f. 

 inner. Med., 1894, xv, 718; Kohler, Centralb. f. inner. Med., 1897, xvm, 

 724; Abderhalden, Zeit. f. physiolog. Chemie, 1898, xxv, 115, and xxvi, 

 65), within limits so narrow, varying as much in individuals as in species, 

 that it seems futile to attempt any generic differentiation (table 23). In 

 all the mammals examined the quantity of hemoglobin in reliable records 

 approximates 32 per cent. 



TABLE 23. The percentage of hemoglobin in the moist erythrocytes in relation to genera. 



THE PERCENTAGE OF HEMOGLOBIN IN THE WHOLE BLOOD IN RELATION 



TO GENERA. 



The percentage of hemoglobin in the whole blood has been made the 

 subject of study by numerous investigators by various methods, but, 

 owing to imperfect methods and other reasons, the figures for a given 

 species are so variable as not to permit of close comparisons of different 

 species. Some have made their estimates by the "extinction coefficient," 

 others by comparison by the colorimetric method, others by the percentage 

 of iron, etc. In determinations by the "extinction coefficient," a weak 

 solution of blood in a layer of given thickness is studied in relation to the 

 extinction of some definite part of the hemoglobin spectrum, usually the 

 second absorption band. These coefficients are proportional to the con- 



