202 



CRYSTALLOGRAPHY OF HEMOGLOBINS OF THE UNGULATES. 



Reduced Hemoglobin of Tragulus meminna. 



Orthorhombic: Axial ratio a : b : c =0.5205 : 1 : 6. 



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



Angles: Prism angle 110 A 1TO=55 (normals); base to prism (001) A 110 = 90. 



Habit tabular on the base, the combination of the prism and base making the 

 rhombic plate (text figures 146 and 147). The orientation of the axes is changed from 

 that in the oxyhemoglobin, the symmetry axis of the monoclinic crystal becoming the 

 macro-axis of the reduced hemoglobin crystal, so that to compare them with the oxy- 

 hemoglobin crystals, the position of these axes must be reversed. Making such reversal 

 the axial ratio of the hemoglobin would be a : b =1.9209 : 1 as against 1.804 : 1 in the 

 oxyhemoglobin; but this difference would be still greater if the true cross-section of 

 the oxyhemoglobin prism were taken. The difference is not only seen in the prism angles, 

 however; the reduced hemoglobin crystals do not show the twinning so characteristic 

 of the oxyhemoglobin. 



Pleochroism is very strong; a is colorless to pale pinkish; b is deep rose-pink; c is 

 deep ruby-red. The extinction is symmetrical on the base and straight on edge views. 

 Looking along the b axis, in convergent light, the biaxial interference figure is seen; the 

 brushes are rather widely separated. The orientation of the elasticity axes is a =b, 

 ba, c=(5, analogous to the arrangement of the elasticity axes in the monoclinic oxy- 

 hemoglobin. The plane of the optic axes is the macropinacoid, the acute bisectrix 

 Bx a = a; the optical character is hence negative. 



A comparison of the characters of the monoclinic oxyhemoglobin and the ortho- 

 rhombic reduced hemoglobin will show their differences at a glance. Such a comparison 

 is given in table 40. 



TABLE 40. Crystallographic characters of oxyhemoglobin and reduced hemoglobin 



of Muis deer. 



ELK OR WAPITI, Cervus canadensis. Plates 34 and 35. 



Two specimens were examined, one probably from the Philadelphia 

 Zoological Gardens and the other from the National Zoological Park at 

 Washington. The first specimen was putrid ; the last was in better condi- 

 tion. Both gave crystals of oxyhemoglobin. The putrid blood was pre- 

 pared without the use of ether, which is likely to produce precipitation in 

 such blood; it was simply repeatedly frozen and thawed, until the cor- 

 puscles were broken down, and then centrifugalized. The crystals formed 

 readily after the slides were covered, and were large enough to photograph 

 inside of a few hours. 



Oxyhemoglobin of Cervus canadensis. 



Tetragonal: Axial ratio a : c =1 : 0.7133. 



Forms observed: Unit pyramid (111), diametral prism (100). 



Angles: 110 A 1TO=90 from outlines of the pyramid in plane; 101 A 101=109 

 (or 71 normals) from outlines of pyramid in elevation; the other elevation looking 

 along the diagonal axis gave about 56 (normals) (55 15' by calculation about). This 

 angle as ordinarily presented appears to be somewhat higher, up to 60 or more. 



