274 CRYSTALLOGRAPHY OF THE HEMOGLOBINS 



Oxyhemoglobin of Cam's azarce. 



Orthorhombic: Axial ratio a : t =1 : 0.4328 from (706) or 1 : 0.4348 from (101). 



Forms observed: Unit prism (110), macrodomes (101), (706), (304). 



Angles: The prism angle was not obtained. The most satisfactory angle was the 

 macrodome 706 A 706=53 35'; the other macrodomes were 101 A T01 =47 measured, 

 46 50' computed from (706) ; also the dome 304 A 304 =36, which agrees almost exactly 

 with calculation from dome (706), as a : 6 for this dome from (706) is 1 : 0.3246 and from 

 36 measured is 1 : 0.3249. 



Habit at first long capillary, later stout prismatic crystals form (text figure 309). 

 The normal crystals are long prismatic (text figure 308), elongated on the vertical axis 

 and longitudinally striated; as is usual in the genus Cam's, the striations are produced 

 by parallel growth. Double crystals, two prisms growing side by side in parallel growth 

 and united on the brachypinacoid, are common in the normal crystals. Owing to this 

 tendency to parallel growth, the crystals become flattened in the direction of the macro- 

 pinacoid, and the square-ended aspect is the common one; the crystal on edge is less 

 frequently seen. Cross-sections were not observed, so that the angle of the unit prism 

 was not obtained. The capillary crystals grow in somewhat radiating tufts, but the 

 tendency of all crystals, whether capillary or thicker, is to aggregate into masses in 

 nearly parallel growth, so that quite large groups are formed, the crystals growing as 

 though united on the brachypinacoid. The circular radiating tufts and spherulitic 

 groups, usually seen in this genus, were not observed in this species. The crystals that 

 formed after the solution came to an equilibrium, which were hence formed more slowly, 

 were shorter and stouter than the larger crystals formed during the first crystallization. 

 The ratio of length to thickness in the normal crystals may be taken at about 20 : 1 on 

 the average; but in these later crystals it was often as low as 5 : 1 or even less. No 

 definite twins were observed. 



The color of the crystals in ordinary light is the usual oxyhemoglobin red. Pleo- 

 chroism is not very strong; the colors are: a pale pink; 6 and c nearly equal and ranging 

 from pale to deep red. The double refraction is fairly strong, and the extinction is straight 

 in all positions. The orientation of the elasticity axes is a=a, b=6, c=< 1 . The inter- 

 ference figure was not observed, but the pleochroism and the double refraction indicate 

 that the acute bisectrix is the axis of greatest elasticity, Bx a =a, and the optical character 

 is hence probably negative. 



Swiss Fox,* Vulpes vulpes (?). Plate 78. 



The specimen of blood was received from the National Zoological 

 Park at Washington, District of Columbia. The blood was very thick and 

 clotted and quite putrid. The clots were destroyed by grinding in sand 

 and the ground mass was diluted with twice its volume of a 50 per cent 

 aqueous solution of egg-white, 1:1; the mixture was then centrifugalized, 

 and from the clear solution thus obtained the slides were prepared as usual. 

 Decomposition continued, however, and considerable granular matter sepa- 

 rated, due to breaking down of the materials in the solution. Crystalliza- 

 tion proceeded rapidly and well-formed crystals of oxy hemoglobin formed 

 along the protein ring and the cover edge, as well as throughout the body 

 of the slide. After 24 hours many of these crystals had passed into reduced 

 hemoglobin by paramorphous change, and many were partly dissolved 

 along the protein ring. Along the cover edge, the crystals were in rather 

 good condition when the photomicrographs were made, about 28 hours 



*This may be "the swift fox, Vidpe veloz, but was marked "Swiss fox," which presumably would be 

 the European fox, Vvlpet vulpes. 



