302 



CRYSTALLOGRAPHY OF THE HEMOGLOBINS 



Habit generally tabular on the clinopinacoid (text figures 363 and 364) ; also short 

 prismatic to tabular on the base. The planes seem to be irregularly developed, and may 

 represent triclinic symmetry. The cover-edge crystals are elongated, apparently on the 

 vertical axis, and generally flattened on the plane of symmetry; they grow crowded 

 together, but as irregular aggregates, not apparently twinned. 



Pleochroism was only observed on the clinopinacoid aspect, and is a pale yellowish, 

 nearly colorless; c deep red. Double refraction is strong; extinction is nearly or quite 

 parallel to the prism edges. The plane of the optic axes appears to be the plane of sym- 

 metry, or parallel to the plane taken as the clinopinacoid. The optical character can not 

 be determined because of insufficient data. 



363 



365 



366 



|c 



FIGS. 363, 364. Pteropus mediut Oxyhemoglobin. FIGS. 365, 366. Vetpertilio jutna Oxyhemoglobin. 



BROWN BAT, Vespertilio fuscus. Plate 95. 



The specimen was bled in the laboratory. The few drops of blood ob- 

 tained were caught in oxalate, and ether-laked. The quantity was not 

 enough to centrifugalize. The slide preparations were made with the laked 

 blood in the usual manner. Crystallization proceeded rapidly, and the 

 ciystals appeared to be rather insoluble, keeping well and showing no 

 tendency to dissolve. Crystallization was quite complete, but little color 

 remaining in the solution. The crystals were shown to be oxyhemoglobin 

 by the microspectroscope. 



Oxyhemoglobin of Vespertilio fuscus. 



Monoclinic: Axial ratio not determinable; /? = 81. 



Forms observed: The three pinacoids only, orthopinacoid (100), clinopinacoid 

 (010), base (001). 



Angles: Base to orthopinacoid, 001 A 100=S1=/?; clinopinacoid, 010 A 100=90. 



Habit tabular on the base, and elongated on the clino-axis, producing broad lath- 

 shaped crystals (text figures 365 and 366), with a ratio of length to width on the base 

 of about 8 : 1 to 5 : 1. The tabular crystals are thin, the thickness is one-twentieth of 

 the length or less. They usually grow singly or sometimes in parallel growth on the 

 base. In some cases the plates pile up on -the base into parallel groups or bundles of 

 crystals. No evidence of twinning was observed. 



Pleochroism moderate; a pale yellowish-red, b rather deep red, c very deep red. 

 Double refraction fairly strong, extinction straight on the basal aspect; on the clinopina- 

 coid aspect the extinction is 16, measured from the basal edge. The orientation of the 

 elasticity axes is a A 6=25, in the obtuse angle; b=b; c A a = 16, in the acute angle. 

 On the base, in convergent light, a single brush of a biaxial interference figure is seen, 

 which passes out of the field upon rotation. As the normal to the base is 16 from n it 

 would appear that the acute bisectrix Bx a = t, and the optical character is hence positive. 



