THE JITIOLOGY OF MALARIAL DISEASES. 437 



pse Lidopictus, but not in various species of 

 Culex. The latter result again obtained later (October 

 4tli, 1899). 



June 28tli, 1899^ Ross stated that Proteosoma scarcely 

 developed in Culex at 21°, and that the growth of the 

 parasites was already slowed at 27° C. in Calcutta. The 

 development of tertian parasites in spotted-winged 

 mosquitoes raised from larvae Avas also observed (letter 

 dated February 22nd, 1899, to Nuttall ; see ' Centralbl. 

 f. Bakteriologie,' vol. xxv, p. 908). 



September, 1899, Bastiauelli and Bignami give a de- 

 tailed description of tertian and crescentic parasites, the 

 publication being accompanied by the best coloured 

 plates hitherto published, illustrating their development. 

 They prove that a single infected Anopheles claviger 

 may communicate malaria (tertian) to man. 



May 4th, 1900, Ziemaun, working in Cameroon, observes the 

 development of the parasites of tropical malaria in 

 two species of Anopheles, as also the development of 

 tertian parasites in one species of Anopheles. He 

 followed the development to the appearance of sporozo- 

 ites in the salivary glands of the insects. He subse- 

 quently (November 22nd, 1900) found that the parasites 

 would not develop in Cimex lectularius nor in sand- 

 flies. 



September, 1900, van der Scheer and van Berlekom, in 

 Holland, observe the development of tertian parasites 

 in A. claviger. 



September 29th, 1900, Man son reported a positive infection 

 experiment with tertian-infected Anopheles (spec. ?) 

 imported from Rome, the insects being permitted to 

 bite his son in London. 



October 6th, 1900, Rees reports a similar experiment to 

 the former. 



After perusing the above chronology, and remembering 

 the question most disputed — the discovery of the develop- 



