VASCULAR SYSTEM 207 



cipitate in the blood of apes but in no other animal be- 

 sides. Nuttall carried this point further and demonstrated 

 the degree of blood-relationship between man and the various 

 apes. With a similar serum he found that the blood of all the 

 anthropoid apes gave quite as great a precipitate as that of 

 man ; the reaction was slightly less pronounced in the Cyno- 

 pitheca (baboons) and cat-like long-tailed monkey, became 

 considerably weaker in the " new world " (platyrrhine) apes, 

 and was totally absent, or barely perceptible, in the Lemuroidea 

 (hesperopitheca). 



Uhlenhuth amplified the experiment by showing that the 

 serum of a rabbit injected with horse's blood will produce a 

 marked precipitate in horses, and a feebler reaction in asses, 

 and in like manner a relationship was established between the 

 ram, goat and ox, between the dog and fox, and so forth. 



The possible application of this reaction in forensic medicine 

 promises to be of considerable value in the examination of 

 bloodstains with a view to determine their human or mammalian 

 origin, and even, if need be, to identify the particular species. 1 



In the human economy there must be a constant " using 

 up "of the blood corpuscles, and the question presents itself, 

 where does the final destruction take place? The liver and 

 spleen are generally recognised as the chief sites of haemolysis. 

 This view is supported by the fact that in the spleen of man 

 and many animals yellowish granules of iron oxide occur, while 

 the proofs of blood destruction in the liver are held to be 



1. The identity of the bile pigment bilirubin with the 

 blood pigment hcematoidin. 



2. Hirt's discovery that in the blood of the hepatic vein the 

 leucocytes are three times as numerous as in the portal vein. 

 The red corpuscles are probably both in the liver and spleen 

 eaten up by the white corpuscles (phagocytosis of erythrocytes). 2 



To make up for the red corpuscles destroyed new ones are 

 formed, primarily perhaps from leucocytes and secondarily 

 from nucleated red cells. There are many centres where 

 this manufacture of erythrocytes may take place, e.g., in the 

 lymphatic glands, the villi of the intestines, in the solitary 

 follicles, and Peyer's patches, in the spleen and thymus, and in 



1 Fortschritte der Medizin, 3, 1904. 2 Munk-Schultz, loc. cit., p. 221. 



