252 



CRYSTALLOGRAPHY OF THE HEMOGLOBINS OF THE 



MUSTELIDi*E. 



FERRET, DOMESTICATED VARIETY OF Mustela putorius. Plates 65 and 66. 



The animal was purchased from a dealer and bled in the laboratory. 

 The blood was oxalated and repeatedly frozen and thawed, then centrif- 

 ugalized, and the slide preparations made in the usual manner. Crystals 

 formed rather slowly, but after 24 hours were sufficiently developed to 

 photograph. Once formed, the crystals were fairly stable and could be 

 preserved for several days at ordinary room temperature. The crystal- 

 lographic examination was made on crystals 48 hours old. Only a small 

 portion of the hemoglobin in solution crystallized, and the mother-liquor 

 remained so strongly colored that determination of the pleochroic colors 

 was difficult. The crystals were oxyhemoglobin, as shown by the micro- 

 spectroscope and color. 



Oxyhemoglobin of Domesticated Variety of Mustela putorius. 



Monoclinic domatic (clinohedrite type): Axial ratio a : 6 : c =1.2799 : 1 : 1.1105; 

 /? = 68. 



Forms observed: Unit prism (110), positive hemiorthodome (101), negative hemior- 

 thodome (101), base (001). 



Angles: Prism edges on base lTO-001 A 110-001=104; negative hemiorthodome 

 to base 101 A 001=50; prism edge to base, edge 1TO-ITO A 001=6S=/3. 



Fios. 264, 265, 266. Muitela putoriuB (var.) Oxyhemoglobin. 



Habit tabular on the base, the plate bounded by the unit prism, and usually one 

 face of each of the hemiorthodomes, at the positive end of the clino-axis (text figure 264), 

 giving a clinohedral symmetry to the crystal when viewed on the base (text figure 265) 

 or when seen on edge looking along the ortho-axis. The crystals were of various sizes, 

 but usually developed rather regularly, so that the thickness of the plates was about 

 one-fifth of the long diagonal on the average, and in the smaller crystals about one-fourth. 

 The crystals twinned on the hemiorthodome (text figure 266). 



Pleochroism is marked on the basal aspect and on edge views looking along the clino- 

 axis, but not so strong on edge view looking along the ortho-axis. Good measurable views 

 looking along the ortho-axis were not seen where the extinction could be measured. The 

 pleochroic colors are a colorless or very pale reddish, b rather deep rose-red, c deep red, 

 the colors of & and c being near together. Extinction is symmetrical on the base and 

 straight when looking along the clino-axis in edge view; the third critical position look- 

 ing along the ortho-axis was not satisfactorily observed. As the extinction when viewed 

 on the plane of symmetry was not determined, the exact orientation of the elasticity 

 axes can not be given; a =b, b is near a, and c is near the normal to the base. The plane 

 of the optic axes is normal to the plane of symmetry, and on the base a figure is seen with 



