278 CRYSTALLOGRAPHY OF THE HEMOGLOBINS 



but the orientation of the elasticity axes is a =a, b =6, c = 6. The plane of the optic axes 

 is, as usual in this genus, the brachypinacoid ; the bisectrix of the optic axes is evidently 

 the axis of greatest elasticity Bx a = a, and the optical character is hence negative. 



GRAY Fox, Urocyon cinereoargenleus. Plate 79. 



Two specimens of the gray-fox blood were examined, both from the 

 National Zoological Park at Washington, District of Columbia. In the 

 blood from specimen I, the usual method of laking with ether, oxalating 

 and centrifugalizing was followed; and in the blood from specimen II 

 one series of preparations was made in the same way. As these crystal- 

 lized rather more rapidly than seemed to be desirable, a second preparation 

 was made from specimen II by adding one volume of a 50 per cent solution 

 of egg-white to the centrifugalized blood before making the slide prepara- 

 tions. This resulted in rather sharper crystals than those at first obtained 

 from this specimen, and also much better than those obtained from speci- 

 men I. In all of these preparations the crystals formed very rapidly and 

 showed no signs of dissolving. They were oxyhemoglobin in all of the 

 preparations made, as determined by the microspectroscope. When received 

 both specimens were somewhat putrid, but still contained mainly oxy- 

 hemoglobin as indicated by the color. 



Oxyhemoglobin of Urocyon cinereoargenteus. 



Orthorhombic: Axial ratio a : b : <!=0.6619 : 1 : 0.2809; a : 6 = 1 : 0.4245. 



Forms observed: Prisms, unit prism (110), macroprism (650), macrodomes (101), 

 (201), macropinacoid (100), base (001) (?). 



Angles: Unit prism 110AlTO=67; macroprism 650 A 630 =57 45'; unit macro- 

 dome 101 A T01 =46; macrodome 201 A 201=80 to 81 (about) (calculated 80 40'). 



Habit of the crystals long prismatic on the vertical axis, but varying somewhat 

 according to the method of preparation. In normal whole blood prepared in the usual 

 manner, as in specimen I, and in the first undiluted preparation of specimen II, the habit 

 is capillary or very long prismatic, as is usual in the crystals formed from concentrated 

 solutions in the genus Cam's. A small number of shorter and thicker crystals appeared 

 in these slides made from the whole blood, which were measurable, and they gave the 

 measurements of the crystals obtained in the blood diluted by addition of egg-white; 

 but these larger, thicker crystals are not so fine as those obtained in the preparations of 

 diluted blood. The prism obtained in the whole blood from specimen I was the unit 

 prism (text figure 316), but from specimen II in the diluted blood the prism (650) seemed 

 to be common in the larger crystals. The capillary crystals formed first in all cases, and 

 gradually became thicker until the ratio of length to thickness might be about 50 : 1; 

 but the thicker crystals which appeared in preparations of the whole blood had a ratio 

 of perhaps 20 : 1, and did not develop from the original capillary crystals. These capillary 

 crystals grow singly, forming a loose felted mass throughout the slide; or in tufts growing 

 from the protein ring and the cover edge, the fibers in the tufts being slightly divergent 

 or nearly parallel. The thicker crystals showed a more nearly normal development, 

 in the preparations of blood diluted with egg-white, and in this state they closely 

 resembled the crystals from the blood of other species of the genus Cam's. They are 

 elongated on the vertical axis and striated longitudinally, evidently on account of the 

 tendency which the crystals have to aggregate in parallel growth. Instead of growing in 

 slightly divergent groups they form masses of many individuals, fifty or more in a bundle 

 in absolutely parallel growth, and frequently showing a strong tendency to flatten upon 

 the macropinacoid. The cross-sections of these prisms often show the composite char- 



