OF THE LEMURS, BABOONS, AND MAN. 313 



LONG-ARMED BABOON, Papio langheldi. Plates 97 and 98. 



The specimen was received from the New York Zoological Park. The 

 blood was clotted and rather putrid. The clots were ground in sand and 

 etherized, the resulting mixture was centrifugalized, and from the clear 

 solution the slide preparations were made. Crystals formed readily and 

 were at first the a-oxyhemoglobin of the genus Papio ; later, crystals of 

 the /3-oxyhemoglobin appeared. The first crystals to appear (a-oxyhemo- 

 globin) showed a tendency to dissolve, and they gradually disappeared as 

 the /3-crystals developed. Both were in the slides at the same time when 

 the crystals first formed, but inside of 4 hours after the preparations were 

 made the /^-crystals greatly predominated. These /^-crystals were more 

 permanent than the a-crystals and kept for several days. 



a-Oxyhemoglobin of Papio langheldi. 



Orthorhombic : No axial ratio deterrninable from the single crystals, a :b : 6 = 

 a : 1 : 0.543 from twins. 



Forms observed: The three pinacoids (100) (010) (001) in the single crystals, and 

 (Oil) in twins. 



Angles: The angles between the pinacoids were measured as 90; from twins, 

 010 A Oil =61 30'. 



Habit tabular on the macropinacoid and elongated on the vertical axis (text figure 

 387), taking the large plane as the macropinacoid. They appear to be laminated, parallel 

 to the large face (100) ; and, on this macropinacoid face, the crystal is marked with 

 lines parallel to the two edges of the plates, due to lamination by parallel growth; on 

 edge views, looking along the axis b the lamination is also visible, the crystal being 

 striated vertically. All cross-sections are rectangular. The lamination of the crystal 

 produced a micaceous structure, and the crystal parted, or cleaved, parallel to the macro- 

 pinacoid. The crystals grew singly, or massed together into irregular aggregates; but 

 were also found in parallel growths of the plates, piled upon each other on the macropina- 

 coid. Some of the groups showed interpenetrant and contact twins on the brachydome, 

 making an angle of about 60; or a six-pointed star, when the twin included both dome 

 faces (text figure 388). The best measurements (which were not very good) gave the 

 angle between the brachypinacoid and the brachydome as 61 30', making the value of 

 <5=0.543 or the ratio of 6 : <! = ! : 0.543. 



Pleochroism strong; a colorless, b old-rose red, c deep red; the colors of b and c 

 being nearly of the same depth, in sections of equal thickness. Double refraction is 

 strong when a is in the section. Extinction is straight in all aspects. Looking along a, 

 a biaxial interference figure is seen, with the brushes not very widely separated. The 

 orientation of the elasticity axes is a = b, b=c, c=a. The acute bisectrix of the optic 

 axes is the axis of greatest elasticity, Bx a = a, and the optical character is negative. 



p-Oxyhemoglobin of Papio langheldi. 



Monoclinic: Axial ratio a : b : 6 =1.655 :!:<!; /3 = 70 30'. 



Forms observed: Unit prism (110), base (001). 



Angles: Prism angle, traces of the edges 110-001 A lTO-001 =62 16'; prism 

 edge to base, edge 110-lTO A 001 =70 30'; in twins, the dihedral angle of the twin 

 edges, corresponding to the above prism edges, is 39. 



Habit tabular, the crystals sometimes flattened on a prism face and elongated on 

 the vertical axis (text figure 389), and sometimes flattened on the base and symmetrically 

 developed on the prism (text figures 390 and 391). The flattening on the prism face 

 gives the unsymmetrical crystals a triclinic appearance, but the symmetrical crystals 

 show distinctly the monoclinic character. The crystals grow singly and in irregular 

 groupings; very frequently twinning on the large plane developed, whether the prism 

 or the base. Contact twins on the prism are common (text figure 392) ; also twins of 



