CRYSTALLOGRAPHY OF HEMOGLOBINS OF THE RODENTIA. 



245 



rather widely separated brushes; in the case of the oblique sections referred to, one 

 brush only appears in the field. As these oblique sections greatly outnumber the normal 

 basal sections, most of the crystals are viewed looking along an optic axis, and being 

 nearly singly refracting in such an aspect they show no pleochroism and the color is 

 pale scarlet, a mean between a and c, or near b. 



BELGIAN HARE, Lepus europceus. Plates 61, 62. 



The living animal was procured and bled in the laboratory, and the 

 oxalated blood centrifugalized to separate the corpuscles. The corpuscles 

 were laked with ether and centrifugalized for 2 hours; from the clear solu- 

 tion thus obtained the slide preparations were made in the usual way. 

 The drops were allowed to dry until a rather thick protein ring formed, 

 and then the preparations were covered. Crystallization proceeded at about 

 the same rate as in the rabbit; the first-formed crystals were rather small 

 and were gradually dissolved as the solution came to an equilibrium. They 

 were mostly rather imperfectly formed. The crystals of the second crop 

 were sharper and of good size; they mostly resembled the a-oxyhemo- 

 globin crystals of the rabbit type (a). Later, soluble crystals of larger size 

 appeared, which seemed to correspond to the /3-oxyhemoglobin of the rabbit. 

 They were very soluble, and were only obtained at a temperature near C. 

 They dissolved so quickly when the temperature rose a few degrees that 

 they were very difficult to measure, even in a room at about the freezing- 

 point; the heat of the body or of the breath destroyed the sharp angles. 

 They were not photographed. These two kinds of crystals are called a-oxy- 

 hemoglobin and /3-oxyhemoglobin, as in the case of the rabbit. 



a? 





252 



253 



254 





255 



FIGB. 252, 253, 254. Lepui europaus o-Oxyhemoglobin. 

 Flo. 255. Lepv* europaus /3-Oxyhemoglobin. 



a-Oxy hemoglobin of Lepus europcBUS. 



Monoclinic: Axial ratio a : b : 6 = 

 0.6588 : 1 : 0.8069; /? = 85 approximately. 



Forms observed: Unit prism (110), 

 clinodome (Oil), orthopinacoid (100), 

 clinopinacoid (010), base (001). Also 

 questionably a pyramid and perhaps a 

 hemiorthodome. 



Angles: Prism angle 110 A 1TO =66 

 (normals); clinodome Oil A Oil =77; 

 clinopinacoid to prism 010 A 110 = 57. 



Habit of the first crystals to form 

 appears to be prism, clinopinacoid, and 

 clinodome (text figure 252) ; but these give place to crystals consisting of prism, clinopina- 

 coid, and base (text figure 253); or prism alone with the base or a hemiorthodome; or 

 prism and orthopinacoid with the clinodome (text figure 254) . The crystals are elongated 

 vertically and striated on the pinacoid faces (orthopinacoid and clinopinacoid) on one of 

 which the crystal is generally flattened. They are liable to be much distorted by 

 irregular development; and in a great many cases are terminated by one oblique face, 

 as though one face of the clinodome. 



Pleochroism is distinct, and on the clinopinacoid aspect is quite pronounced; a is 

 yellowish-red; b and c are nearly equal and deep red or paler red according to the thick- 

 ness. On the clinopinacoid section, the extinction angle is 15, measured from the prism 

 edge; on sections in the zone 100-001, the extinction is straight. On the section looking 

 along the clinodome, or along a about, one brush of the biaxial interference figure is 

 seen. From the position of this brush it looks as though the acute bisectrix was a and 



