434 GEORGE H. P. NUTTALL. 



the second of the three species uamed can serve as a 

 host for human malarial parasites. The coincidence in 

 the geographical distribution of ague and malaria-bear- 

 ing mosquitoes in Italy^ as claimed repeatedly by Grassi, 

 has been disproved by Celli. The claim that this geo- 

 graphical agreement would probably be found to hold 

 in other parts of the world has been disproved by Nut- 

 tall, Cobbett, and Strangeways-Pigg (1901) in England. 

 We cannot, therefore, accept Grassi^s statement that he 

 discovered the malarial mosquito because of its geo- 

 graphical distribution, pretty and ingenious as the 

 hypothesis seemed in the beginning. It seems certain 

 that Grassi was after all entirely guided by Ross's pub- 

 lication of December 18th, 1897, in which he describes 

 an insect with spotted wings and eggs like those which 

 characterise Anopheles. 



November 6th, 1898, Infection Experiment on Man. — 

 Grassi mentions that Bignami had made an infection 

 experiment by means of mosquitoes (the three species 

 above named were employed) collected at Maccarese, 

 a malarious locality. The result was positive in this 

 case, the person acquiring aestivo- autumnal fever. 

 (Several infection experiments were subsequently car- 

 ried out by Bignami, Bastianelli, and Grassi in colla- 

 boration, these being reported in various papers of 

 later date. The first experiment did not prove which 

 species harboured the parasites, and of itself was insuf- 

 ficient to establish the theory on a firm basis.) 



December 4th, 1898, Bastianelli, Bignami, and Grassi 

 observed the development of crescentic parasites 

 in Anopheles claviger, the appearances correspond- 

 ing to those described by Ross for Proteosoma on the 



in favour of the mosquito-malaria hypothesis. In the paper read on the next 

 day at the Accademia del Lincei, under the same title as that which appeared 

 in the ' Policlinico,' Grassi omits to mention Ross, though he refers to what 

 was known regarding Texas fever. The paper, published in the 'Transac- 

 tions' of the Accademia, differs in several respects from that which appeared 

 in the 'Policlinico.' 



