INSECTS AND HUMAN DISEASE 109 



on the margins of the Porto Swamp, which had been at 

 one time the famous hexagonal dock, built by the Emperor 

 Trajan. They were all specimens of Anopheles maculi- 

 pennis, and were carefully examined to see that they had 

 only just emerged from their pupal cases and had not yet 

 fed. They were then infected on cases of tertian fever, 

 this type of malaria being selected because it offers no real 

 danger, and is easily cured by quinine. The patients 

 employed were very carefully and repeatedly examined, so 

 as to absolutely exclude the possibility of their suffering 

 from any other type of malarial disease. 



" The transmission of the infected mosquitoes from Rome 

 to London was a matter of some difficulty. The journey from 

 Rome to London lasted about three and a half days. So 

 many unfavourable conditions of temperature, shaking, etc., 

 having to be experienced on the journey, it was necessary 

 to devise some apparatus that would obviate these risks 

 as much as possible. I noticed in my visits to the houses 

 and stables of Ostia, that the Anopheles there collected 

 very often, and seemingly by preference, rested on the old 

 cobwebs, and maintained their position on these delicate 

 structures with ease, even while the latter were wafted 

 about by fairly strong currents of air, so I tried to repro- 

 duce a similar condition as far as possible in my arrange- 

 ments for transmission. Mosquito netting was loosely 

 applied round a framework of tinned wire, so as to form 

 a cylinder eight and a quarter inches long, by three and 

 a half inches in diameter, which might be closed at both 

 ends by means of strings. Four such cylinders were placed 

 within a square wooden box to protect them from damage 

 (fig. 30), to render them more portable, and to keep the 

 insects in a state of semi-obscurity. On each one of the 

 sides of the box an opening, three inches square, was made, 

 covered with wire netting, to allow of the transmission of 

 air, and also to prevent the mosquitoes escaping should the 

 cotton netting in any way get torn. By means of this 



