286 CRYSTALLOGRAPHY OF THE HEMOGLOBINS 



Pleochroism is usually rather marked in all aspects, except the cross-sections of 

 the prism; a pale rose-pink, 6 deep rose-pink, c deep blood-red, inclining to carmine. 

 Extinction is straight or symmetrical in all aspects. The orientation of the elasticity 

 axes is a=a, b=b, c=<J. The plane of the optic axes is the brachypinacoid; on the 

 basal sections, the biaxial figure is seen with the axes widely separated; the angle 2E 

 was not exactly measured, but was above 75. The vertical axis is the acute bisectrix 

 Bx a =c, and the optical character is positive. 



JAGUAR, Felis onca. Plates 84 and 85. 



The specimen of blood was obtained from the National Zoological 

 Park at Washington, District of Columbia, and was dark in color and in a 

 slightly putrid condition. It was oxalated and repeatedly frozen and 

 thawed to lake it; finally, a little ether was added to complete the laking, 

 and the blood centrifugalized for several hours. From the clear solution 

 thus obtained drop preparations were made on slides as usual. Only 

 crystals of oxyhemoglobin formed at first; these were of two forms, plates 

 or tabular crystals, a-oxyhemoglobin, and octahedral crystals, /^-oxyhemo- 

 globin. The slides were kept at a temperature near the freezing-point, 

 and when brought into a warm room the crystals rapidly dissolved; this 

 was especially the case with the octahedral crystals. All examinations, 

 therefore, had to be made at about the freezing-point, and the photo- 

 graphs were taken in a room temperature of C. Rod-like crystals, evi- 

 dently sections of the plates on edge, were seen along with the plates. From 

 a second preparation, made later from the same prepared blood, crystals 

 of reduced hemoglobin were obtained in the form of rods with imperfect 

 ends. These reduced hemoglobin crystals were not measurable. 



a-Oxy hemoglobin of Felis onca. 



Orthorhombic: Axial ratio a : 6 : t =0.7813 : 1 : 1.2146. 



Forms observed: Unit prism (110), macropinacoid (100), brachypinacoid (010), 

 base (001); rarely the macrodome (101) and brachydome (025). 



Angles: Prism angle 110 A 110=76 (normals); macropinacoid to base 100 A 

 001=90; macrodome angle 101 A 101=65 30'; brachydome 025 A 025 =51 45'. 



327 



* ^^ ^\. /^ .s ^V \ f 



/ 325 \ // \\ / 



Ib 



FIGS. 324,325. Felis onca a-Oxyheiuoslobin. FIGS. 320,327. Felis onca 0-Oxyhemoslobin. 



Habit tabular on the base, the usual crystal consisting of this plane, bounded by 

 the macropinacoid and the unit prism (text figures 324 and 325). The tabular crystals 

 are elongated in the direction of the macro-axis and grow together in parallel growth in 

 the direction of the two axes in the basal pinacoid. They also pile up on the base. By 

 this method of parallel growth large groups occur with the same orientation throughout 

 the groups. The macrodome was not observed, except in the case of a very few plates 



