132 CRYSTALLOGRAPHY OP HEMOGLOBIN IN RELATION 



bream, pike, horn-fish, herring, lark, raven, and pigeon, and of man. He 

 records that hemoglobin of various animals crystallizes in various forms and 

 systems, and that he always obtained rhombic plates from the blood of man 

 and many species of lower animals, regular 6-sided plates from the blood of 

 the mouse and squirrel, tetrahedra from the blood of the guinea-pig, and 

 prismatic crystals from the blood of the rabbit. Crystals from various kinds 

 of blood which appear to possess a similar form still showed unmistakable 

 differences in the sizes of the angles. From his investigations he reached the 

 conclusion that the bloods of individual species have something specific 

 and characteristic about them, so that it is occasionally even possible to 

 determine the species of animal from whose blood the crystals were derived. 

 Where, as in the case of human blood, as described by Funke, there appear 

 to be two or more kinds of crystals in the same blood, Bojanowski considers 

 that one of them is the characteristic form and the others undeveloped 

 crystals. Thus, in human blood what he describes as the "right-angled 

 plate" is, he believes, the characteristic form, while the "prisms and rhombic 

 plates" are regarded as undeveloped forms of the right-angled plate. The 

 descriptions given are very brief and incomplete: thus, the crystals from 

 the dog are described as "rod-like crystals forming closely woven nets," 

 and from the cat as "very regular three-sided rods," etc. The description of 

 the crystals of dog's blood would apply equally well to any species whose 

 hemoglobin crystals are rather insoluble, if the hemoglobin crystallized in 

 prisms, for such hemoglobins form felted masses of capillary or long pris- 

 matic crystals. The prisms of reduced hemoglobin of the cat are not 3- 

 sicled, but nearly rectangular in section. 



After a latent period in the study of the crystallography of hemoglobins 

 for the 5 succeeding years the first contribution by Preyer appeared (Archiv 

 f. ges. Physiologic, 1868, i, 395), which was shortly followed by his now 

 classic and authoritative memoir (Die Blutkrystalle, Jena, 1871). When 

 the former contribution was published blood crystals from 47 species of 

 vertebrates had been recorded, and of these in only 10 cases had the crys- 

 tal system been recorded. In his memoir these 47 species are enumerated 

 and the data concerning them are given. Preyer evidently regarded the 

 crystals obtained from different species as differing from one another, but 

 he concluded with Rollett that they may all be included in the two crystal 

 systems, the orthorhombic and the hexagonal. He states that "besides 

 the crystal system there are other distinctions, as, for instance, the sphe- 

 noidal crystal of the guinea-pig, the 4-sided prisms of the dog, the 4-sided 

 prisms and rhombic plates of man. These peculiar morphological shapes 

 are obtained only from each animal, even after repeated recrystallizations; 

 a definite form is peculiar to each animal and can not be changed to another 

 form. The same holds good with solutions of hemoglobin. Yet little im- 

 portance is to be attached to statements on the crystallographic differences 

 of the hemoglobin of different animals, because neither is the same method 

 of crystallization always used, nor is the blood always capable of being 

 compared, nor has the measure of the crystallizability of any optional sub- 

 stance been found. ^It is the same with decomposability as with crystalliz- 



