248 CRYSTALLOGRAPHY OF THE HEMOGLOBINS OF THE 



Of the family Procyonidoe, the species from which crystals were exam- 

 ined were the kinkajou, Cercoleptes caudivolvulus, and the cacomistle, 

 Bassariscus astuta. The blood of the raccoon was experimented with early 

 in our work, but no satisfactory crystals were obtained. They no doubt can 

 be produced by the use of a suitably modified process of preparation, such 

 as we have resorted to in our more recent work. 



The family Ursidce is represented by three species, the black bear, 

 Ursus americanus; the polar bear, Ursus maritimus, and the sloth bear, 

 Melursus ursinus. Their crystals all closely resemble each other, and are 

 characterized by the peculiar cyclic trillings already alluded to as being 

 found in this group and in the Otariidce. All belong to the same class of 

 crystals, monoclinic hemimorphic or monoclinic sphenoidal, which has 

 thus far been seen only in this family and in the Otariidce and Phocidce, but 

 may very possibly occur in the otters and ferrets also, although they have 

 been determined as monoclinic hemihedral, or domatic (clinohedral group 

 of Dana). 



PHOCIDiE. 



HARBOR SEAL, Phoca vitulina. Plate 62. 



Specimens of blood of the harbor seal were received from the Phila- 

 delphia Zoological Gardens, from the National Zoological Park at Washing- 

 ton, District of Columbia, and from the Zoological Garden at Detroit, Mich- 

 igan. In each case the blood was not quite fresh, but all were in fairly good 

 condition and were not putrid, except in the case of the specimen from 

 Detroit, which was slightly putrid. The blood from Washington was frozen; 

 all of the specimens were treated in the same manner with this exception. 

 The bloods were oxalated, ether-laked, and centrifugalized, generally from 

 2 to 3 hours; and from the clear solution thus obtained the slide prepara- 

 tions were made. The crystals formed slowly at room temperature, and 

 rather more rapidly at a temperature near freezing, but the color of the 

 solution remained a deep red, showing that much of the oxyhemoglobin 

 was still in solution. The crystals were kept at temperatures near the 

 freezing-point, but when brought into the warm room did not appear to 

 dissolve, and even on the stage of the photomicrographic apparatus they 

 did not lose their form. The solution was very deeply colored and of about 

 the color of the crystals, which were oxyhemoglobin. 



Oxyhemoglobin of Phoca vitulina. 



Monoclinic hemiruorphic, or monoclinic sphenoidal (tartaric acid type) : Axial 

 ratio 0:6: (5 = 1.2131:1 : 1.1970; /? = 75. 



Forms observed: Unit tetartopyramid (Til), unit hemiprism (1TO), orthopinacoid 

 (100), base (001). 



Angles: Unit prism to unit pyramid edges on base, edges 1TO-001 A llT-001 =101, 

 or traces of unit prism edges lTO-001 A TTO-001 =79, and the traces of the unit pyramid 

 on the base give the same angle. The angle ,3 on sections parallel to (010) or 100 A 001 = 

 75; and the angle of the trace of the unit pyramid on the same section or 101 A 001 =52. 



Habit tabular on the base, the crystal consisting of the basal pinacoid bounded 

 by the positive unit pyramid at the positive extremity of the ortho-axis and by the unit 

 prism at the negative extremity of this axis (text figures 256 and 257). In many cases 

 the orthopinacoid developed, but it was not always present. Sometimes this orthopina- 



