. Carnegie Institution of Washington publication. CRYSTALLOGRAPHY OP HEMOGLOBINS OF THE RODENTIA. 229 Oxyhemoglobin of Fiber zibethicus. Monoclinic: Axial ratio a : b : t = : 1 : 6; /? = 68°. Forms observed: Unit prism (110), base (001). Angles: Prism angle 110 A HO =63°; prism edge to base, edge 110-lTO A 001 =68° =/?.. 204 206 Flos. 203, 204, 205, 206. Fiber zibethicu» Oxyhemoglobin. Habit thin tabular on the base, the crystal consisting of the base (001) bounded by the prism (110). The first crystals to form are long needles or lath-shaped crystals with oblique ends; among these soon
. Carnegie Institution of Washington publication. CRYSTALLOGRAPHY OP HEMOGLOBINS OF THE RODENTIA. 229 Oxyhemoglobin of Fiber zibethicus. Monoclinic: Axial ratio a : b : t = : 1 : 6; /? = 68°. Forms observed: Unit prism (110), base (001). Angles: Prism angle 110 A HO =63°; prism edge to base, edge 110-lTO A 001 =68° =/?.. 204 206 Flos. 203, 204, 205, 206. Fiber zibethicu» Oxyhemoglobin. Habit thin tabular on the base, the crystal consisting of the base (001) bounded by the prism (110). The first crystals to form are long needles or lath-shaped crystals with oblique ends; among these soon appear blade-like crystals of the same habit, often twinned; and, at about the same time, lozenge-shaped tabular crystals appear all through the slides. These latter (text figures 203 and 204), which are undistorted crystals, are very symmetrical rhombic plates, sometimes untwinned, sometimes twinned repeatedly. They do not seem to form mimetic twins and develop into hexagonal plates, as is so commonly the case with rodents. The twins are of the usual horse-type (text figure 205), on a twin axis normal to a prism-base edge and lying in the base. But in the blade-like crystals these appear as contact twins with the common prism-like edge parallel to the length of the blade-like crystal; the blades being elongated in the direction of two oppo- site prism faces, and consisting, therefore, of the two basal faces and two prism faces and terminated by the prism faces. This elongation produces in the untwinned crystals a triclinic appearance. In these same blade-like crystals another kind of twinning is very commonly seen, on a unit pyramid as the plane of twinning, the twin being inter- penetrant and showing an X-shaped cross-section (text figure 206). These were also observed in the plates. The twins of the plates are, as stated, of the usual horse-type, but the plates being very symmetrical the group formed by the twinning has often the outline of a truncated triangle, and some
Size: 1941px × 1287px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcarnegieinstitutionof, bookcentury1900, bookdecade1900
