214 CRYSTALLOGRAPHY OF HEMOGLOBINS OF THE UNGULATES. 



Pleochroism is marked; a pale yellowish-red, nearly colorless, b red, c deep cochi- 

 neal-red. Extinction on the ordinary crystals is oblique, except on the rods, which show 

 the orthopinacoid aspect. In this aspect the extinction is straight; and in convergent 

 light one brush of a biaxial interference figure appears in the field, somewhat eccentri- 

 cally placed and revolving with the revolution of the crystal. The orientation of the 

 elasticity axes is a A <!=30 about; b = b, c A a =5 45'. The extinction angle on the 

 (010) aspect is hence 30; on the usual oblique aspects it is 18 to 23, measured from 

 the prism edges. The plane of the optic axes is the clinopinacoid and the angle of the 

 axes, IE, must be between 50 and 60. The bisectrix of the optic axes is c, Bx a = c, 

 and the optical character is hence positive. 



Reduced Hemoglobin of Ovis nahura. 



Orthorhombic : a : b : 6 =0.885 : 1 : t. 



Forms observed: Unit prism (110), base (001). 



Angles: Prism angle 110 A 1TO = S3; prism to base 110 A 001=90. 



Habit thin tabular on the base, the plane bounded by the prism faces (text figures 

 172 and 173) ; and the ratio of the short diagonal on the base to the prism length is about 

 5:1. The crystals occur singly, or sometimes piled up on each other on the basal sur- 

 face; and appear somewhat fan-shaped in edge view, but twinning was not observed. 

 These crystals did not occur in large numbers in any of the slides. 



Pleochroism is marked; a nearly colorless, 6 purplish-red, c very deep purplish- 

 red. Extinction is symmetrical on the base and straight on all edge views. The orien- 

 tation of the elasticity axes is, a = b, b=<!, c=a; the plane of the optic axes is hence the 

 basal pinacoid. Looking along the axis of greatest elasticity, a, the biaxial interference 

 figure is seen; the separation of the axes 2E is about 50. The acute bisectrix is hence 

 a, Bx a = a, and the optical character is negative. 



BULLOCK OR Ox, Bos taurus. Plate 44. 



Fresh blood was obtained from the abattoir, oxalated, the corpuscles 

 settled by centrifugalizing and the plasma drained off. The corpuscles 

 thus nearly freed of plasma were then laked with ether, and the solution 

 saturated with ammonium oxalate and centrifugalized. The slide prepa- 

 rations were made as usual, the drops being allowed to evaporate so that a 

 thick protein ring was formed. Crystals formed slowly at room tempera- 

 ture, and they appeared to be somewhat porous and imperfect. They were 

 fairly permanent, however, and the photographs were made 2 days or more 

 after the slides were prepared. The spectroscope showed only oxyhemo- 

 globin. Several preparations were made, varying the amounts of oxalate 

 and the treatment in laking; but the first-formed crystals were all about 

 of the same type. As the solution became more dense in the slides, by 

 evaporation through the seal of balsam, the crystals developed more faces 

 and changed slightly in habit. Only crystals of oxyhemoglobin appeared. 



Oxyhemoglobin of Bos taurus. 



Orthorhombic: Axial ratio a : b : c =0.7467 : 1 : 0.619. 



Forms observed: Unit prism (110), brachyprism (120), brachydomes (Oil), (054), 

 macrodome (302), pyramid (221). 



Angles: Unit prism 110 A H0=7330' (normals); brachyprism 120 A 120 = 112 

 30' (normals); brachydomes Oil A Oil =63 30' (normals); 054 A 054=54 (normals); 

 macrodome, 302 A 302=75 roughly; edge angle of pyramid over pole, edge 221-221 A 

 221-221=99 about. 







