OTARIID.E, PHOCIVM, MUSTELID.E, PROCYONID^E, AND URSIDyE. 259 



regular tubes. Specimen I was rather thick and slightly decomposed; it was 

 laked with ether and centrifugalized, and from the clear solution the slide 

 preparations were made as usual. Specimen II was clotted and very slightly 

 putrid ; it was ground up in sand, with the addition of ether, and the mix- 

 ture centrifugalized. This gave a clear solution from which the slide prep- 

 arations were made. Both crystallized in the protein ring soon after the 

 covers were applied, but the crystals in each case showed a tendency to 

 dissolve; and 24 hours later crystals of much larger size appeared along the 

 cover edge. The first crystals were of the same type, a peculiar trilling that 

 was found in all crystals of bears that were examined; the second crop of 

 larger crystals were single, or in parallel growth, rather than twinned. All 

 of the crystals were at first oxy hemoglobin, but the solution showed traces 

 of metoxyhemoglobin in specimen II, and later crystals of this material 

 developed in both preparations. They seemed to be paramorphs of the 

 oxyhemoglobin, however, and did not differ very much in their angles from 

 the oxyhemoglobin crystals, although the prism angle was slightly larger, 

 as will be seen below. 



Oxyhemoglobin of Ursus americanus. 



Monoclinic hemimorphic, rnoiioclinic sphenoidal (tartaric-acid type) : Axial ratio 

 a : 6 : (! =1.2239 : 1 : 1.1429; /? = 755' (calculated). 



Forms observed: Unit pyramid (111), unit prism (1TO), clinopinacoid (010), base 

 (001), and in twins, prism (230). 



Angles: Traces of the unit prism or the unit pyramid on the base, the edges 110- 

 001 A nO-001=7S30'=the angle between the edges llT-001 A Tll-001; from sec- 

 tions looking along the edges 1TO-001 or Tll-001 the angles of 1TO A 001=79, and 

 Til A 001 =46 47. 



Z87 



( IV 



286 



FIGS. 283, 284, 285, 286, 287. Ursus americanus Oxyhemoglobin. 



Habit of the first crystals to form (in and about the protein ring) squarish tabular 

 on the base and consisting of the forms, base (001), unit prism (1TO) on one end of the 

 binary axis, and unit pyramid (Til) on the other end (text figures 283 and 284), the one 

 being the analogous pole and the other the antilogous pole. These crystals are found 

 occurring singly or in trillings (text figures 286 and 287), the three individuals in the 

 trilling growing with their unit prism edges pointing in towards the center of the group 

 and with the edges formed by the unit pyramid pointing outward, but each member 

 of the group overlapping or tilted in the same sense against the adjacent member, in 

 cyclic order, the relative position of the three individuals being comparable to that of the 

 three blades of a screw-propeller (text figure 286). The vertical axes of the three indi- 

 viduals are parallel, and the composition face is evidently the prism (230), whose angle, 

 calculated from the axial ratios, is 60 35'. This form was not observed as a crystal plane. 



