Groivth and Sporulation of Tertian Malarial Parasites. 77 



7. Beichenow, E. " Hceraogregarina stepaiwici — Die Entwicklungsgeschichte einer 



Heemogregarine," ' Archiv fur Protistenkunde/ 1910, vol. 20, pp. 252-350. 



8. Eow, B, " The Development of the Parasite of Oriental Sore in Cultures," ' Quart. 



Journ. Micros. Sci.,' 1909, vol. 53, Part IV. 



9. Splendore, A. " Um novo Protozoo Parasita de Conigli," ' Bevista da Societa 



Scientifica de Sao Paulo,' 1909, vol. 3, Xos. 10-12, pp. 109-112. 

 10 Yakimoff, W. L., and Kohl-Yakinioff, Nina. "Toxoplasma cants," 'Archiv fur 

 Protistenkunde,' 1912, vol. 27, pp. 195-206. 



The Groivth and Sporulation of the Benign and Malignant 

 Tertian Malarial Parasites in the Culture Tube and in 

 the Human Host. 



By John Gordon Thomson, M.A., M.B., Ch.B. Eciin. (Pathologist to the 

 Royal Southern Hospital, Liverpool, and Durning-Lawrence Research 

 Student); and David Thomson, M.B., Ch.B. Edin., D.P.H. Cantab. 

 (Clinical and Pathological Eesearch Assistant, School of Tropical 

 Medicine, Liverpool). 



(Communicated by Sir Ronald Ross, K.C.B., F.R.S. Received May 21, — Read 



June 12, 1913.) 



[Plate 10.] 

 Prefatory Note. 



Researches on the cultivation of the parasites of malaria in Liverpool were 

 commenced some time ago at my suggestion by Dr. Sinton, and then, with 

 better success, by Drs. J. G-. Thomson and McLellan, and by Dr. D. Thomson. 

 We are greatly obliged to Sir Edwin Durning-Lawrence, Bart., for giving us 

 the services of Dr. J. Gr. Thomson for this important enquiry. — Ronald Ross, 

 21st May, 1913. 



Introduction. 



The successful cultivation of malarial parasites was first announced by 

 Bass and Johns (1912). Since then several workers, Thomson and McLellan 

 (1912), Thomson, J. G., and Thomson, D. (1913), and Ziemann (1913), have 

 successfully repeated these cultivation experiments. This achievement has 

 led the way to new discoveries regarding the malarial parasite, and suggests 

 that it may be possible to cultivate in vitro any protozoal parasite, however 

 specialised it may be. 



