210 



CRYSTALLOGRAPHY OF HEMOGLOBINS OF THE UNGULATES. 



about double the width; but some are much more elongated, and others are reduced to 

 nearly square tabular plates. They frequently show parallel growth, uniting on the 

 brachypinacoid or on the macropinacoid and also grow in irregular, somewhat radiating 

 aggregates. 



Pleochroism is rather strong; a is pale yellowish-red; & is deep blood-red, c is deep 

 red, somewhat deeper than b. Extinction is straight in all aspects. The orientation of 

 the elasticity axes is a=a, b=c, c=6. The plane of the optic axes is the base, and a is 

 the acute bisectrix, Bx a =a. Looking along this axis of a, the interference figure is seen in 

 convergent light, with the angle between the optic axes, 2E =40. The optical character 

 is negative. 



10 



160 



162 



161 



163 



Fias. 160, 161. Gtuella dorcae O.xyliemoglobin. FIG. 162. Cephalophus yrimmi a-Oxyhemoglobin. 

 Flo. 163. Cephalophut grimmi /3-Oxyhemoglobin. 



DUICKERBOK, Cephalophus grimmi. Plate 40. 



The specimen was received from the National Zoological Park at 

 Washington. The blood was oxalated, laked with ether, and centrifu- 

 galized, and preparations were made in the usual manner. The slides were 

 kept at a temperature of about C., and soon were filled with the small 

 pyramidal crystals, which showed a tendency to dissolve, and were hence 

 examined and photographed at temperatures near the freezing-point. 

 Later, the slides developed the second kind of crystals, the hexagonal plates. 

 Both kinds of crystals were oxyhemoglobin. 



a-Oxyhemoglobin of Cephalophus grimmi. 



Tetragonal: Axial ratio a : c =1 : 0.8687. 



Forms observed: Unit pyramid (111), also traces of (100). 



Angles: Between the pyramid edges in the horizontal plane, normal to the axes = 

 110 A 1TO = 90; between the pyramid edges in the vertical axial plane (calculated) = 

 101 A T01=9S, observed angle of pyramid over the pole = lll ATTl=77. 



Habit pyramidal (text figure 162), the crystals occurring singly or in irregular 

 groups and in parallel growths. Twinning seems to occur on the pyramid as the plane 

 of twinning. 



The color is the normal oxyhemoglobin red; pleochroism is scarcely noticeable. 

 Double refraction is weak, but the extinction is symmetrical on the aspects normal to 

 the vertical axis. Looking along this axis, the crystals are singly refracting in parallel 

 polarized light and do not polarize; but in convergent light they show a faint dusky 

 uniaxial cross. By the quartz wedge it is seen that the vertical axis is the direction of 

 greater elasticity, hence w > s and the optical character is negative. 



