CHAPTER XII. 



CRYSTALLOGRAPHY OF THE HEMOGLOBINS OF THE 



UNGULATES. 



The hemoglobins from 20 species of the ungulates were studied, of which 

 only 2 belonged to the perissodactyls and the remaining 18 species to the 

 artiodactyls. 



The perissodactyls examined were the horse, Equus caballus, and the 

 mule, a cross between Equus asinus male and Equus caballus female. The 

 crystals of these two species closely resemble each other, but those of the 

 mule are distinguishable by measurement from the crystals of the horse. 

 Unfortunately, the blood of Equus asinus was not obtained for examina- 

 tion, so that whether the hemoglobin of the cross is intermediate between 

 that of the horse and the ass could not be determined. 



The artiodactyls examined included the hippopotamus, 2 species of 

 peccary, the common swine, a chevrotain, 5 species of the Cervidce or deer, 

 4 antelopes, 2 species of sheep, and 2 species of the genus Bos, the ox and 

 the buffalo, or bison. These represent the principal families of the Artio- 

 dactyla except the Camelidce and Giraffidce. Of the Hippopotamidce but 

 one species was examined, the Hippopotamus amphibius. Of the Dicotyl- 

 idce, the two species were the white-lipped peccary, Dicotyles labiatus, 

 and the collared peccary, Dicotyles tajacu. The chevrotain was the muis 

 deer, Tragulus meminna, a small deer-like animal. As will be seen, its 

 crystals do not resemble those which were obtained from the true deer of 

 the family Cervidce. The deer included 4 species of the genus Cervus, the 

 wapiti or elk, the red brocket deer (?), the Venezuela deer, and the fallow 

 deer; also the muntjak of the genus Cervulus, C. muntjak. 



Of the Bovidce, the subfamily Antilopince is represented by 4 species, 

 belonging to the genera Antilope, Cervicapra, Gazella, and Cephalophus. 

 The subfamily Ovince is represented by the common sheep and the bharal 

 or blue sheep of Thibet, both belonging to the genus Ovis ; these two species 

 will be found to resemble each other very closely and to differ from all of 

 the other ungulates examined. They both show a very remarkable type of 

 twin crystal, a fiveling that produces a pentagonal composite crystal, that is 

 practically unique. It may be called the sheep-type of twin. The subfamily 

 Bovince is represented by the ox, Bos taurus, and the buffalo, Bos bison. 



The crystal systems represented in the hemoglobin crystals of the 

 ungulates include the monoclinic, orthorhombic, hexagonal, and tetrag- 

 onal systems, and it will be seen that the optical characters (with the 

 exception of one case in which the character is questionably determined, 

 and the single example of the hexagonal, in which it could not be deter- 

 mined) bear a certain definite relation to the crystal system. Thus the 



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