254 



PHYSIOLOGICAL CHEMISTRY 



of over one hundred species of animal and subsequently studied the 

 characteristics of the crystals very minutely from the standpoint of 

 crystallography. Their findings may prove of importance from the 

 standpoint of heredity and the origin of species. 



FlG. 76. OXYHEMOGLOBIN CRYSTALS FROM BLOOD OF THE NECTURUS. 



Reproduced from a micro-photograph furnished by Prof. E. T. Reichert, of the University 



of Pennsylvania. 1 



Carbon monoxide hemoglobin 



HEMOGLOBIN 



Acid hematin (+ globin) 



r; 



Hemin 

 (Hematin hydrochloride) 



Hemochromogen 

 Methemoglobin 



Alkaline hematin (+ globm) 



Hemin 



(Hematin hydrochloride) 



Acid hematoporphyrin (+ iron) 



.2 



3 

 < 



Alkaline hematoporphyrin 



1 The micro-photographs of oxyhemoglobin (see pages 251-254) and hemin (see page 

 (265) are reproduced through the courtesy of Professors E. T. Reichert and Amos P. Brown, 

 of the University of Pennsylvania, who have investigated the crystalline forms of 

 biochemic substances. 



