208 



CRYSTALLOGRAPHY OF HEMOGLOBINS OF THE UNGULATES. 



rather faster than in horse blood for example, and the first crystals to form 

 were rather long rods. These formed at a temperature of about 24 C. ; 

 on placing the slides in the cold, a second crop of larger and stouter crystals 

 formed, which appear to be more soluble than those of the first crop, dis- 

 solving readily when brought into a temperature much above 12 C. When 

 placed in the cold, the corroded edges and angles that were produced by 

 the increase of temperature are soon repaired. The crystals of the first 

 crop do not seem to be affected by such temperature change as would cause 

 solution of the second crop. Examination with the spectroscope failed to 

 show any difference in the spectra of these two types of crystals; and they 

 have identical axial ratios, although the habit is quite different. After some 

 days the terminations of the crystals of the first crop became imperfect 

 or even dissolved; but this occurred while they were kept in the cold. 

 The crystals of the second crop seemed to keep very well, so long as the 

 temperature was kept below 10 C. ; at a few degrees above this tempera- 

 ture they began to dissolve. About two weeks after the slides were pre- 

 pared they showed mainly very large crystals of prismatic habit, somewhat 

 similar to the first crop, but with the ends corroded. From cross-sections 

 these were evidently unit prisms, of the character of those formed in the 

 first crop of crystals. 



Oxyhemoglobin of Cervicapra redunca. 



Orthorhombic : Axial ratio a : b : I =0.839 : 1 : 0.5877. 



Forms observed : Unit prism (110), brachypinacoid (010), macropinacoid (100) (?), 

 macrodome (101), brachydome (032), unit pyramid (111). 



Angles: Prism angle 110 A 110=80 (normals); macrodome 10lAl01=69 

 (normals); brachydome 032 A 032=43 (normals); unit pyramid edges over the pole 

 or unit brachydome Oil A Oil =54. The value for 6, calculated from the macrodome 



(first crop), was 0.5870 and from the pole edge angle 

 of the unit pyramid (second crop) was 0.5S77, which 

 are substantially identical. 



Habit of the first crop crystals (text figure 157) 

 is long prismatic, consisting of the unit prism (110) in 

 equilibrium with the brachypinacoid (010), and termi- 

 nated by the unit macrodome (101); the second crop 

 crystals are short prismatic, becoming tabular by de- 

 velopment of the brachypinacoid as they become larger, 

 and consisting of the unit prism (110) and the brachy- 

 pinacoid (010) in the prismatic zone, terminated by 

 the brachydome (032) (text figure 158) ; or in some 

 cases by the unit pyramid (111) (text figure 159). In 

 some crystals the macropinacoid seemed to be devel- 

 oped, probably by pressure of the cover. The prismatic 

 crystals, found in the slides that had been standing in 

 the cold for two weeks, were of the first type; but the 

 brachypinacoid was much reduced in size and the terminations were wanting. Small 

 crystals developed a few days after the slides were prepared, which showed the same 

 habit, and, even with the brachypinacoid entirely absent, these were terminated by the 

 unit macrodome. The first crop of crystals grew from the edges of the cover and from the 

 protein ring in irregular tufts, also in radiating stellate groups through the body of the 

 slide; and the mass of the crystals into which the protein ring was converted were of this 

 type. The second-crop crystals appeared near the edge of the cover, singly or in roughly 



157 







158 



159 



FIGB. 157, 158, 159. Cervicapra rerfuncoOxy- 

 hemoglobin. 



