. Carnegie Institution of Washington publication. OF THE DOGS, WOLVES, AND FOXES. 267 Habit prismatic, elongated parallel to the vertical axis, and the prism terminated by the flat dome (101) (text figure 293) or sometimes by the base (text figure 294). The first crystals to form are usually hair-like, but stouter crystals later develop along the protein ring and the cover edge. These stouter crystals may also appear in the body of the slide, and may even be doubly terminated. They are often seen to be composite, by parallel growth in the zone of the vertical axis; and are strongly striated in
. Carnegie Institution of Washington publication. OF THE DOGS, WOLVES, AND FOXES. 267 Habit prismatic, elongated parallel to the vertical axis, and the prism terminated by the flat dome (101) (text figure 293) or sometimes by the base (text figure 294). The first crystals to form are usually hair-like, but stouter crystals later develop along the protein ring and the cover edge. These stouter crystals may also appear in the body of the slide, and may even be doubly terminated. They are often seen to be composite, by parallel growth in the zone of the vertical axis; and are strongly striated in this direction, because of the parallel growth. Cross-sections are rare, and almost never appear in measurable form until the slides are several days old. The ratio of length to thickness varies from 500 : 1 in the hair-like crystals, down to 20 : 1 in some of the stouter crystals. Twinning was not observed, but a parallel growth, in which the crystals grow together upon the brachypinacoid, is very commonly seen. In such groups two prisms are seen in perfectly parallel orientation, and united side by side on the brachy- pinacoid. This is a character quite common in all of these rod-like orthorhombic crystals in other species also. Pleochroism is marked; a nearly colorless, 6 rather pale red, c deep red. Double refraction is strong; and extinction is straight in all side views and symmetrical on cross-sections of the prism. The orientation of the optic axis a=a, b=6, c=6. No interference figure was observed; but, from the relative elasticities in different directions, it would appear probable that the optical character was negative and the acute bisectrix Bxa=a. (3-Oxyhemoglobin of Cam's familiaris. Monoclinic: Axial ratio not determined, ,3=78°. Forms observed: Unit prism (110), clinopinacoid (010), orthopinacoid (100), basal pinacoid (001). Angles: Orthopinacoid to base 100 A 001=78°=/?; the prism angle appears to be acute on a or a > 6, but no cross-sections were found
Size: 1064px × 2349px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcarnegieinstitutionof, bookcentury1900, bookdecade1900
