l82 DYNAMICS OF LIVING MATTER 



Until about thirty years ago the idea was held generally that a trans- 

 fusion of the blood of an animal into the veins of a human being was 

 permissible or advisable in the case of severe loss of blood. We know 

 to-day that in such cases physiological salt solutions or human blood 

 must be injected, and that the blood of animals is generally toxic. This 

 important discovery was made by Landois,* who showed that blood of a 

 foreign species generally destroys the red corpuscles of the animal into 

 which it is infused. He investigated systematically the destructive 

 force of foreign blood upon the red corpuscles of various animals, and 

 made the remarkable discovery that there exists a striking relation be- 

 tween this effect and the blood relationship of animals. I will quote 

 the summary of this part of his investigation: "My results include a 

 point which is of importance for the systematic order of animals; 

 namely, that those animals which are closest to "each other in regard to 

 their anatomical qualities also possess the most homogeneous blood, 

 inasmuch as a transfusion of blood between two closely related animals 

 brings about the least rapid destruction of the foreign blood. The 

 transfusion thus offers us a means of determining in questionable cases 

 the relationship of animals. A transfusion of blood is possible between 

 varieties of the same species ; the blood of species that are very close to 

 each other shows hemolysis only very gradually, and the animals with- 

 stand large quantities of foreign blood; the more distant, however, 

 animals are, the more violent the effects of the foreign blood become" 

 (p. 289). The hemolysis consists in the red blood corpuscles becoming 

 permeable for the hemoglobin they contain, which begins to diffuse 

 out. The red blood corpuscles become in consequence pale (ghosts or 

 shadows). It is obvious that this diffusion of the hemoglobin is rendered 

 possible through some chemical alteration of the blood corpuscle. The 

 experiments of Landois prove that the blood of closely related species 

 is chemically and physicochemically more nearly identical than the 

 blood of more distant forms. More recently the observations of Landois 

 were taken up by Friedenthal,t Gruenbaum, and Nuttall.J These 

 experimenters were able to avail themselves of Bordet's precipitation 

 method. Bordet had found that after serum of a foreign species has 

 repeatedly been injected into a rabbit, a precipitation will occur when 

 blood of that foreign species and the blood of this rabbit are mixed. 

 Moreover, the same reaction occurs when blood from an animal related 

 to the one whose serum had been injected is mixed with the blood of 

 the rabbit. Friedenthal and Nuttall used this reaction to find out the 



' Landois, Die Transfusion des Blutes, Leipzig, 1875. 



t Friedenthal, Engelmann's Archiv, p. 494, 1901 ; and Berliner klinisch-therapeup- 

 tische Wochenschrift, 1904. 



X G. Nuttall, Blood Immunity and Blood Relationship, Cambridge, 1904. 



