OF THE CATS AND CIVETS. 287 



similar to those taken as macrodome and brachypinacoid in the case of the lion. From these 

 the macrodome angle was obtained and the axial ratio computed. The only form of crys- 

 tal aggregate noted was the parallel growth described; no form of twinning was observed. 

 The tendency towards elongation along the macro-axis produces long parallel growths 

 and drawn-out crystals; when these are on edge they appear to be prismatic crystals. 

 The color on the basal pinacoid face is a rather deep scarlet-red, owing to the slight 

 pleochroism in this aspect; but when seen on the edge views the pleochroism is rather 

 strong. The colors are: a pale yellowish-red, & rather strong red, c deeper red. Extinc- 

 tion in all aspects is straight or symmetrical. In convergent light, on the base, the 

 biaxial interference figure is seen, with the brushes widely separated and the plane of 

 the optic axes the macropinacoid. The orientation of the elasticity axes is a =6; b=a; 

 c=6. The acute bisectrix of the optic axes is the axis of greatest elasticity; Bx a = a, 

 the optical character is hence negative. 



p-Oxyhemoglobin of Felis onca. 



Isometric, normal (perhaps pseudo-isometric only). 



Forms observed: Octahedron (111) ; cube (100); dodecahedron (110). 



Angles: Octahedron angle 111 A TTl =70 30' (actual angle); dodecahedron 

 angles 110 A 1TO=90. 



Habit octahedral or dodecahedral; in minute octahedra or clodecahedra (text 

 figures 326 and 327), rarely combined with the cube. These crystals appeared after 

 the crystals of a-oxyhemoglobin, but were found with them in the same slide; they 

 developed along the cover edge. 



Color rather bright scarlet-red; not pleochroic. They show no double refraction 

 and do not polarize in any position. Convergent light had no effect upon them. They 

 are evidently isotropic. 



Reduced Hemoglobin of Felis onca. 



Orthorhombic (?): No axial ratio could be determined. 



Forms: A prism or two vertical pinacoids, the prismatic crystals have a nearly 

 square section. 



Angles: No good measurements of angles were obtained. 



Habit prismatic, long square prisms, often ending in a brush of fibers at the end 

 and sometimes looking like a bundle of crystals. 



Rather pleochroic, extinction parallel to the length in all aspects. These crystals 

 resemble the reduced-hemoglobin needles that appeared in lion blood; and, like them, 

 they appeared in blood that had been kept for some days. 



The /?-oxyhemoglobin crystals were very likely mimetic isometric, but no evidence 

 of this was seen. Similar, apparently isometric, and perfectly isotropic crystals were 

 seen to develop in the blood of the mountain-lion, and all stages of the development of 

 these crystals were observed in that species, so that their mimetic character was deter- 

 mined. In the bob-cat, or wild cat, similar mimetic crystals, also apparently isometric, 

 were noted. In all of these American cats this character of forming mimetic twins seems 

 to be common and normal. 



MOUNTAIN-LION OR PUMA, Felis concolor. Plates 85 and 86. 



The specimen of blood was received from the National Zoological 

 Park at Washington, and was in a very fresh condition. It was evidently 

 fresh blood and showed only oxyhemoglobin. The blood was laked with 

 ether, and centrifugalized for several hours; from the clear solution thus 

 obtained the slide preparations were made in the usual manner. The 

 blood crystallized quite readily, about as fast as in the case of the domestic 

 cat. The first crystals to develop are short prismatic crystals; these are 

 followed by small pyramidal crystals and very thin tabular crystals, almost 



