14 PROTOZOOLOGY 



other organisms, until 1828, when Dufour's account of the gregarine 

 from the intestine of coleopterous insects appeared. Some ten years 

 later. Hake rediscovered the oocysts of Eimeria stiedae. A flagellate 

 was observed in the blood of salmon by Valentin in 1841, and the frog 

 trypanosome was discovered by Gluge and Gruby (1842), the latter 

 author creating the genus Trypanosoma for it. 



The gregarines were a little later given attention by Siebold (1839), 

 KoUiker (1848) and Stein (1848). The year 1849 marks the first rec- 

 ord of an amoeba being found in man, for Gros then observed Enta- 

 moeba gingivalis in the human mouth. Five years later, Davaine 

 found in the stools of cholera patients two flagellates (Trichomonas 

 and Chilomastix). Kloss in 1855 observed the coccidian, Klossia heli- 

 cina, in the excretory organ of Helix ; and Eimer (1870) made an ex- 

 tensive study of Coccidia occurring in various animals. Balantidium 

 coll was discovered by Malmsten in 1857. Lewis in 1870 observed 

 Entamoeba coli in India, and Losch in 1875 found Entamoeba histo- 

 lytica in Russia. At the beginning of the last century, an epidemic 

 disease, pebrine, of the silkworm appeared in Italy and France, and a 

 number of biologists became engaged in its investigation. Foremost 

 of all, Pasteur (1870) made an extensive report on the nature of the 

 causative organism, now known as Nosema bombycis, and also on the 

 method of control and prevention. Perhaps this is the first scientific 

 study of a parasitic protozoan to result in an effective practical 

 method of control of its infection. 



Lewis observed in 1878 an organism which is since known as 

 Trypanosoma lewisi in the blood of rats. In 1879 Leuckart created 

 the group "Sporozoa," including in it the gregarines and coccidians. 

 Other groups under Sporozoa were soon definitely designated. They 

 are Myxosporidia (Biitschli, 1881), Microsporidia and Sarcosporidia 

 (Balbiani, 1882). 



Parasitic protozoology received a far-reaching stimulus when 

 Laveran,(1880) discovered the malarial parasite in the human blood. 

 Smith and Kilbourne (1893) demonstrated that the Babesia of the 

 Texas fever of cattle in the southern United States was transmitted 

 by the cattle tick from host to host, and thus brought to light for the 

 first time the close relationship which exists between an arthropod 

 and a parasitic protozoan. Two years later, Bruce discovered Try- 

 panosoma brucei in the blood of horses and cattle suffering from 

 "nagana" disease in Africa, and in the following year he showed by 

 experiments that the tsetse fly transmits the trypanosome from host 

 to host. Studies of malarial diseases continued and several important 

 contributions appeared. Golgi (1886, 1889) studied the schizogony 



