FRITZ 8CHAUDINN 277 



blood corpuscles. The sanitary recommendations then recommended 

 by him against malaria were adopted by the Austrian government. 

 Further, he made observations on the biology of the mosquito that 

 carries these protozoa. Then he worked out a blood parasite of the 

 lizard, and discovered a Rhizopod, Leydenia, in the ascites fluid of man. 



His next step was to study the parasites of the human colon, 

 which had been called Amaiba coli. Schaudinn discovered that this 

 really is two distinct species, one of which is harmless, while the other, 

 Entamoeba histolytica, he proved to be the cause of human bloody 

 dysentery. 



His following contributions were devoted to the study of blood 

 parasites, so-called hgemosphoridia. His initial memoir upon this 

 subject was one of his most important. He studied the three blood- 

 parasites of the owl, known as Proteosoma, Halteridium and Hcema- 

 mozba, which he proved to be stages of one and the same life cycle 

 and to be flagellates and not sporozoa. Here also may be mentioned 

 his conclusion that the organisms of human malaria are also flagel- 

 lates. In connection with this study he worked out the biology of 

 the mosquito (Culex pipiens) that infects the owl, and its mode of 

 transference of the parasites. In his investigation of Spirochete 

 ziemanni he made the important discovery that the two main forms 

 of blood flagellates, Spirochcete and Trypanosoma, are not bacteria, but 

 flagellates, a discovery that has wonderfully clarified our knowledge 

 of blood diseases. 



In 1904 Schaudinn left Rovigno to enter the National Sanitary 

 Commission at Berlin. He was fully recognized as the foremost in- 

 vestigator of Protozoan diseases, and though he had never studied 

 medicine he became its consultant authority in Germany. Unwisely 

 the German government for a time placed hindrances to his free 

 initiative, and forced him to undertake certain work outside of his 

 proper field; he had no choice but to accept these conditions, for he 

 was a poor man with a family to support. Principles of patriotism 

 decided him to decline a call to the professorship of protozoology 

 recently started by the British government for the investigation of 

 tropical diseases. At this time Schaudinn corroborated the interest- 

 ing discovery of Looss, that the round worm Ankylostomum infects 

 the mammalian host not through the mouth, but by entering the 

 skin then being transported by the blood current to the lung, and 

 thence to the intestine. 



Perhaps what is the most important medical discovery made by 

 him was that of 1905, when he found in the secretions of syphilitic 

 growths a parasitic flagellate that he named Spirochcete pallida. Long 

 had physicians searched for the cause of this disease, one of the most 

 widespread and terrible of human disorders, and it was the crown- 

 ing act of Schaudinn's life to have found it. 



