CRYSTALLOGRAPHY OF HEMOGLOBINS OF THE UNGULATES. 211 



^-Oxyhemoglobin of Cephalophus grimmi. 



These crystals develop after the pyramids of the a-oxyhemoglobin. They are in 

 the form of very thin hexagonal plates (text figure 163), occurring both singly and also 

 growing in groups, often with the orientation of parallel growth. They are evidently 

 hexagonal, the angle of the plate being 120 (60 normals) and the sides square with 

 the terminal plane. No axial ratio could be determined, as the combination of forms is 

 simply unit prism (10TO) and base (0001). They are singly refracting when viewed on 

 the base, but too thin to give an interference figure. On edge view they show very weak 

 double refraction and extinguish parallel to the base. The optical character could not 

 be determined owing to the very weak double refraction. 



SHEEP, Ovis aries. Plates 40-42. 



The fresh blood was collected in oxalate from the abattoir, and centri- 

 fugalized to throw down the corpuscles. The plasma was drained away, 

 the corpuscles were laked with ether, oxalate added almost to saturation, 

 and the solution centrifugalized for 2 hours. From the clear liquid the 

 slide preparations were made as usual. The preparation crystallized at 

 room temperature, and the crystals showed no tendency to dissolve. Some 

 crystals were obtained within 5 hours of making the preparations. The 

 crystals at first formed were fine needles, but soon tabular crystals began 

 to appear. Several other preparations were made from the same blood, 

 and in all the crystals kept well. After about a week, crystals of reduced 

 hemoglobin began to make their appearance, along with the crystals of 

 oxy hemoglobin, which formed in the freshly prepared slides. These crystals 

 of reduced hemoglobin, like the oxyhemoglobin, were not dissolved on slight 

 increase of temperature. The slides were kept cool, at about 10 C., except 

 when under examination. Both the oxyhemoglobin and the reduced 

 hemoglobin were identified by the spectroscope. 



Oxyhemoglobin of Ovis aries. 



Monoclinic: Axial ratio a : b : 6 =1.140 : 1 : 0.970; /?=54. 



Forms observed: Unit prism (110), positive hemiorthodome (T01), base (001), 

 clinopinacoid (010), orthopinacoid (100). 



Angles: Prism angle 110 A HO, traces on the base, or angle of edges 110-001 A 

 110-001= 82 30' (actual angle); orthodome to orthopinacoid T01 A 100=72; ortho- 

 pinacoid to base 100 A 001 = 54 = /? (normals). 



Habit of the first crystals to form minute needles without definite outlines, tapering 

 to a point at either end; with these soon appear tabular crystals consisting of the base 

 with a very short prism, tabular on the base (text figure 164). After about a day, long 

 prismatic crystals appear consisting of the three pinacoids, elongated parallel to the 

 vertical axis and generally flattened on the orthopinacoid. These sometimes show the 

 prism as a bevel on the edges (text figure 165), but more often are simply the three pina- 

 coids. These crystals twin and form networks of rods, and frequently on the orthopina- 

 coid faces twin growths develop, producing a cross-banded effect due to the strong 

 pleochroism. Twins are hemitrope, on the orthopinacoid (100) and on the hemiortho- 

 dome (10T), the two occurring together and making fivelings of exactly pentagonal shape 

 (text figure 166). These little fivelings grow on the sides of the long crystals, or singly, 

 scattered through the slides; and they grouped themselves along the crystals of oxalate 

 that formed in some of the slides, strung like beads along the needles of the oxalate. 

 In this occurrence they present edge views to the observer. When seen in side view they 

 are generally more or less perfect pentagons, divided by the contact planes into five 



