OF THE MARSUPIALIA, EDENTATA, AND SIRENIA. 



181 



Reduced Hemoglobin of Dasyurus maculatus. 



Monoclinic: Axial ratio a : b : 6 = 1.8227 : 1 : t ; /? about 63. 



Forms observed: Prism (110), base (001), positive hemiorthodome (T01), orthopina- 

 coid (100). 



Angles: Traces of prism on the base, edge 110-001 A 1TO-001 =57 30'; prism 

 edge with base, edge 110-lTO A 001=63 about. The angles of the hemiorthodome 

 with base were not obtained, as it occurred only occasionally and not in good position 

 for measurement. It was nearly normal to this prism edge. 



Habit of the crystals at first long prismatic, the prism terminated obliquely by 

 the base (text figure 77), later the prisms become thick, and finally thin tabular crystals 

 develop by extension parallel to the basal pinacoid. These latter (text figure 78) have 

 the usual rhombic shape of the hemoglobin crystals of the species with angles near 60. 

 A crystal showing the hemiorthodome and orthopinacoid is shown in text figure 79. 

 They form parallel growths, but twinning was not observed. The prismatic crystals 

 grow in tufts and radiating groups; the plates generally grow singly or in simple parallel 

 growths. Some of these may be twins on an axis normal to a prism-base edge, with the 

 base as composition face. 



Pleochroism is very strong, as is commonly the case with hemoglobin; a colorless, 

 6 rose-red, c purplish-red. Extinction measured from the prism edge is nearly straight 

 in all cases, so that in prismatic crystals the extinction appears to be straight and only 

 varies about one degree from parallelism with the edge of the prism when looking along 

 the ortho-axis. But in the plates, when seen on edge, the extinction is 28 with the 

 trace of the base, or with the a axis when looking along the ortho-axis. The elasticity 

 of b and c appears to be nearly equal, and looking along a the double refraction is rather 

 weak. The optic axes lie in the plane of symmetry and the orientation of the optic axes 

 is a A a =28, in the obtuse angle; 6=6; c A (5 = 1, in the acute angle. The small 

 angle between c and 6 makes the extinction appear nearly parallel with the prism edge 

 or the axis 6. A brush of the interference figure was seen emerging nearly parallel to the 

 clino-axis a, and this would indicate that Bx a was a, which the double refraction also 

 indicates. The optical character is hence very probably negative. 



77 



80 



81 



FIGS. 77, 78, 79. Dmyurus maculatits Reduced Hemoglobin. FIGS. 80, 81, 82, 83. Dasyurus viverrinus Oxyhemoglobin. 



AUSTRALIAN CAT, Dasyurus viverrinus. Plate 19. 



The specimen of blood was received from the National Zoological Park 

 at Washington. The blood was oxalated, frozen repeatedly, and centrif- 

 ugalized without any addition of ether. Crystals formed readily at ordi- 

 nary room temperature, and were very sharp. They showed no signs of 

 dissolving with change of temperature, and they were evidently not very 

 soluble. The spectroscope showed them to be oxyhemoglobin. 



