CHAPTER XVII. 



CRYSTALLOGRAPHY OF THE HEMOGLOBINS OF THE 

 INSECTIVORA AND CHIROPTERA. 



One species of the Insectivora, the mole, Scalops aquaticus, and two 

 species of the Chiroptera, or bats, were studied. One of the bats belonged 

 to the Megachiroptera, the flying-fox or fruit-bat of India, Pteropus medius; 

 and the other to the Microchiroptera, the common brown bat, Vespertilio 

 fuscus. In each case but a very small amount of blood was available, so 

 that the clearing of the blood from extraneous matter was difficult. But 

 the hemoglobins of the three species examined were all rather insoluble, so 

 that fairly good crystals were obtained. As the three species mentioned 

 are rather widely separated zoologically, their hemoglobin crystals would 

 not necessarily bear much resemblance to each other; nevertheless, the 

 crystals of the two bats show some resemblance to each other, both being 

 apparently monoclinic. 



All of the species are widely separated zoologically from the other 

 animals examined, and both groups are highly specialized animals; so that 

 the crystals do not show much resemblance to others that were studied, 

 and the crystals obtained from the mole are practically unique. Like the 

 hemoglobins of other animals living largely underground, the crystals of 

 the mole are very insoluble, and they keep, in the presence of ether, for a 

 long period. But unlike the hemoglobins of other burrowing animals that 

 crystallize in the monoclinic or orthorhombic systems, these mole crystals 

 were fairly well formed and sharp, not simply hairs or trichites, as is so 

 common in these insoluble hemoglobins. This comes from the fact that 

 the habit of the crystals is pyramidal and not prismatic. 



The blood of the flying-fox was in a putrid condition when received, 

 and while it crystallized readily, the crystals were not stable. So far as 

 form is concerned they are quite different from those of the little brown bat; 

 but if the blood had been fresh, it is possible that a different habit of crystal 

 might have developed that would have shown more resemblance to those ob- 

 tained from the blood of the brown bat. This fruit-bat blood was examined 

 early in our work, and before we had perfected methods for regenerating 

 putrid blood. 



The very few examples of these two orders examined preclude any 

 attempt at generalization as to their affinities, but it may be remarked that 

 there is a strong superficial resemblance between the lath-shaped mono- 

 clinic crystals of the oxyhemoglobin of the brown bat, Vespertilio fuscus, 

 and the similarly shaped a-oxyhemoglobin crystals of the genus Papio of 

 the Primates. These latter, however, are orthorhombic. 



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