290 CRYSTALLOGRAPHY OF THE HEMOGLOBINS 



LEOPARD-CAT, Felis bengalensis. Plates 86 and 78. 



The specimen of blood was received from the New York Zoological 

 Park, and was clotted and very putrid. The clots were ground in sand 

 and subjected to an atmosphere of oxygen before centrifugalizing. No 

 ether was used for fear of breaking down the hemoglobins, as the blood 

 was so putrid. From the clear centrifugalized solution the slide prepara- 

 tions were made as usual. Crystals of reduced hemoglobin formed slowly, 

 and with them a few imperfect crystals of oxyhemoglobin. The crystals 

 of reduced hemoglobin were at first small but very numerous; as more 

 crystals developed, some of these grew to rather large size and a few reached 

 relatively enormous proportions. The crystals of oxyhemoglobin were 

 small, pyramidal in shape, and were rare. The reduced-hemoglobin crystals 

 did not show any tendency to dissolve and remained sharp, but the crystals 

 of oxyhemoglobin gradually disappeared from the slides by solution. 



Reduced Hemoglobin of Felis bengalensis. 



Orthorhombic: Axial ratio a : b : I =0.9657 : 1 : 0.3667. 



Forms observed: Unit prism (110), macrodomes (101), (403). 



Angles: Prism angle 110 A 110=88: macrodomes 101 A T01=4135'; 403 A 

 103 =53 30'. 



Habit prismatic on the vertical axis, consisting of the square prism of 88 and the 

 flat macrodome (text figure 334) ; the ratio of length to thickness of the prism is about 

 5 : 1 on the average, but many are much shorter, and 2 : 1 is common. Cross-sections 

 of the prism are frequently seen, and also other irregular sections, that are sometimes 

 quite symmetrical, and produce false planes, by the cover and slide interfering with the 

 development of the crystal. Thus, many oblique sections of the square prism are seen, 

 which look quite monoclinic, and some even rhombohedral. This sometimes occurs by 

 the growth of a crystal that rests upon one of the dome faces ; as it grows larger, it loses 

 the other pair of dome faces, and an apparent rhombohedron results. Parallel growth 

 is normal in some crystals and skeleton groups are formed, by extension of the crystal 

 group in the plane of the macropinacoid, and in such a way that the diagonals of the 

 single crystal in this plane become the growth axes of the group in parallel growth. 

 Thus, the X-shaped groups are formed shown on plate 87, fig. 519. Twins do not 

 appear to form commonly, but a few interpenetrant twins on the pyramid as twin plane 

 were observed (text figure 335). 



Pleochroism is marked, particularly on the side views of the prism; when seen in 

 end view the pleochroism is not so strong. The colors are: a nearly colorless or with a 

 tinge of pinkish-lilac, b deep rose pink, c deep purplish-red, or, when thinner, deep 

 purplish-rose color. Double refraction is strong, and the extinction is straight in all 

 aspects. On the cross-sections of the prism the biaxial interference figure is seen with 

 well -separated brushes, with the angle 2E about 50; but the cross is rather dusky. The 

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

 brachypinacoid; the acute bisectrix of the optic axes is the axis of least elasticity, Bx a = c, 

 hence, the optical character is positive. 



Oxyhemoglobin of Felis bengalensis. 



Tetragonal: Axial ratio a : 6 =1 : 1.9253. 



Forms observed: Unit pyramid (111). 



Angles: Angle over apex 111 A III =40 20' (actual angle); angle of pole edges 

 over apex =54 50', observed (computed 54 54'); angle of horizontal edges = 90. 



Habit pyramidal, apparently a tetragonal unit pyramid (text figure 336), but the 

 crystals are not very sharp. They have a granular appearance as though undergoing 



