DIFFERENT KINDS OF HEMOGLOBINS FOUND. 323 



but pure methemoglobin, as Menzies shows, has quite a different spectrum. 

 The material that we have described as methemoglobin gave the spectrum 

 of the substance described by Menzies as "pure methemoglobin." He is 

 inclined to regard the me toxy hemoglobin as a mixture of methemoglobin 

 and oxyhemoglobin, but as it crystallizes in a different form from either, 

 in the same blood, it probably should be regarded as a separate substance. 

 It may be identical with the substance that has been described as "acid 

 hemoglobin." It is converted into oxyhemoglobin by the addition of a 

 little alkali, such as ammonia, but exposure to air does not change it to 

 oxyhemoglobin; on the contrary, exposure of oxyhemoglobin to air con- 

 verts it into this metoxyhemoglobin. It seems to be a condition of the 

 hemoglobin in which the oxygen is held more closely than in oxyhemo- 

 globin, a sort of "resting stage" of the hemoglobin, in which it is inactive 

 as either an oxidizing or a reducing agent. 



It was found in the case of many species that the fresh blood would 

 first crystallize in one form of oxyhemoglobin; that later a second crop of 

 crystals would appear having a totally different habit and even crystal 

 system, or, in other words, different constitution; and that sometimes 

 this would be succeeded by a third crop having a still different form. Many 

 examples of this dimorphism or trimorphism are recorded in the foregoing 

 descriptions of species. They are distinguished as a-oxy hemoglobin, /3-oxy- 

 hemoglobin, y-oxyhemoglobin, etc. For instance, in the baboons three 

 distinct crops of oxyhemoglobin crystals developed: (1) tabular or lath- 

 shaped orthorhombic crystals; (2) short prismatic to tabular monoclinic 

 crystals; and (3) tabular orthorhombic crystals. It is possible that (1) 

 and (3) may be the same substance, but very unlikely; (2) is evidently a 

 different substance. In the same genus two forms of methemoglobin were 

 observed, one orthorhombic and one monoclinic, corresponding to the 

 a- and /3-oxy hemoglobins, but varying from them in angles and axial ratio. 

 Among the rodents, two forms of oxyhemoglobin were observed in a num- 

 ber of species; in some cases these may be really the same substance, as 

 will be explained later on; in others, they are evidently different substances. 

 Thus, in the blood of the domestic rabbit, an orthorhombic and a monoclinic 

 form of oxyhemoglobin are found that are evidently different; and the 

 same is true of the blood of the capybara, porcupine, and ground-hog. 

 Indeed, in the blood of this last species, Marmota monax, three forms of 

 oxyhemoglobin develop: (1) a-oxyhemoglobin, hexagonal; (2) /3-oxyhemo- 

 globin, orthorhombic; and (3) y-oxyhemoglobin, monoclinic; but two of 

 these may possibly be the same substance. Two kinds of oxyhemoglobin 

 were observed in the blood of the jaguar, Felis onca, and in the puma, 

 Felis concolor; and two forms of reduced hemoglobin were found in the 

 blood of the lynx, Lynx canadensis. In the jaguar and puma the two kinds 

 are, one orthorhombic, and the other, isometric or pseudo-isometric; in 

 the lynx, the two kinds are orthorhombic and tetragonal. 



In several of the ungulates two forms of oxyhemoglobin or CO-hemo- 

 globin were observed. In the horse and mule the oxyhemoglobin crystal- 

 lizes (1) in orthorhombic prisms and (2) in monoclinic tabular crystals; 

 the CO-hemoglobin is also dimorphous and crystallizes in the same respec- 



