FRIEDENTHAL'S EXPERIMENTAL PROOF OF 
BLOOD-RELATIONSHIP:! 
HERBERT W. RAND. 
IN recent years important evidence in favor of Darwin's 
theory of the descent of man has increased. Eugen Dubois 
found in Pithecanthropus erectus the much-sought-for missing 
link between man and living anthropoid apes. Selenka has 
shown that, of the catarrhine apes, the living anthropoid apes 
resemble man in having a placenta discoidalis capsularis, while 
all other catarrhines have a placenta bidiscoidalis. Ernst 
Haeckel has accumulated evidence showing that man has 
descended from a line of extinct catarrhines whose immediate 
ancestors belonged to the group of tailless anthropoid apes, 
and whose more remote ancestors belonged to the Cynopithe- 
cini. The evidence’ afforded by comparative paleontology, 
comparative embryology, and comparative anatomy agrees in 
supporting Darwin’s hypothesis. 
To all this evidence is now added evidence depending upon 
the similarity in chemical composition of the blood of closely 
related animals. Comparative chemical analyses of blood are 
attended with great difficulties because of variations in the 
blood depending upon the varying conditions of nutrition in 
the animal. Landois, in his researches on the effects of 
animal blood transfusions upon human diseases, attributed his 
failures, so far as the beneficial effects of the blood transfusion 
upon the disease-were concerned, to the dissolving of the red 
blood corpuscles of the injected blood by the blood of the 
recipient. Experiments upon lower animals, in the way of 
ome animal of a remote species, led to 
injecting blood from s : 
The animals 
the same results as the experiments upon man. 
by Hans Friedenthal: Ueber einen experi- - 
1 An extended abstract of a paper Gees DLE PU 
mentellen Nachweis von Blutverwandschaft, Archiv für Anatomie u Dy f1- 
ologie, physiologische Abtheilung, Hefte 5 und 6, 1900. 
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