300 CRYSTALLOGRAPHY OF THE HEMOGLOBINS 



INSECTIVORA. 



MOLE, Scalops aquaticus. Plate 94. 



Two specimens of mole blood were obtained from animals procured 

 in the suburbs of Philadelphia. One was bled in the laboratory. The 

 fresh blood from this latter specimen was oxalated, ether-laked and centrif- 

 ugalized as usual. The other was from a dead animal, and the clotted 

 blood from the heart and larger vessels was removed, the clots ground in 

 sand with ether and a little oxalate, and the resulting mixture centrif- 

 ugalized. The slide preparations were made as usual. The preparations 

 from the fresh blood crystallized so quickly that only very small crystals 

 were obtained; that from the clotted blood crystallized somewhat less 

 rapidly and furnished larger crystals. The crystals in any given prepara- 

 tion varied only slightly in size, when obtained from the fresh blood; and 

 they kept for a very long time, showing no tendency to dissolve. The crystal- 

 lization of the oxyhemoglobin was almost complete, and no color remained 

 in the solution in the slides. In a test-tube, with a little ether, the crystals 

 of the fresh blood in the plasma kept for several months. From the stale 

 blood, on the other hand, the crystals in the slides were attacked by bacteria 

 inside of a few days, and completely honej^combed by their action, the 

 interior of the crystal being converted into reduced hemoglobin inside of 

 a shell of oxyhemoglobin. In some cases the crystals were completely 

 converted into reduced hemoglobin, no shell of oxyhemoglobin remaining. 

 The change was, however, a paramorphous one, and the crystals were not 

 at all altered in form, only the optical characters being changed by the 

 alteration to reduced hemoglobin. The preparation of fresh blood preserved 

 in a tube at ordinary temperature for as much as 3 months did not produce 

 any larger crystals, but the habit changed slightly after a long period. 



Oxyhemoglobin of Scalops aquaticus. 



Hexagonal (pyramidal ?): Axial ratio a : c =1 : 3.2931. 

 Forms observed: Unit pyramid (1011), base (001). 



Angles: Angle of the pole edges of the unit pyramid, measured over the apex, 

 average, gave 33 47'. 



FIGS. 360, 361, 362. Scalopi aqualicus Oxyhemoglobin. 



Habit, rather short pyramidal crystals; consisting of the tapering unit pyramid, 

 cut off by the base and making a "barrel-shaped" crystal (text figure 360). The basal 

 planes are rather large so that the pyramid is truncated to about one-third of what its 

 length would be if complete. In crystals formed in the fresh blood, however, the trim- 



