260 DISCUSSION.
The work described in the paper of Lt.-Col. Birt makes one think more about these short fevers, and I hope it will induce other men in the endemic areas to endeavour to try to trace out some of these forms. He has rightly and kindly quoted the work of Kilroy as an example in which very complete and careful experiments were carried out as to the
transmitability of the virus by the phlebotomus, and such work wants to be carried out more fully.
In going further East, in reference to the question of dengue, the first experience that I had in Bombay was very suggestive indeed. During eighteen months at Bombay, in the naval defence ship, we had three epidemics of fever of this so-called seven-day or dengue type. Personally, I think it was dengue. The ca.ses had definite characteristics : sudden onset of fever, marked rise of temperature, always marked pain, and most of them shewed evidence of rash. These rashes were often not very definite, but they were found to be present if looked for carefully. I may say that in the early series of patients many of the rashes were not recognised, because they were not sufficiently looked for. These cases were very interesting. Every series of men that came out from England, on arrival in the ship, appeared, almost without exception, to contract the disease. On three separate occasions the three drafts were all attacked, there being no immunes among those coming from England. It was not as though the disease was restricted to the ship, for cases were found on the other ships of the flotilla when the men were living quite separately. The disease was not restricted to the hot weather, but the cases occurred in December and March as well as in the middle of the year. Part of the time the ship was in dock where mosquitoes were very abundant, and by these the disease might well have been conveyed. Besides these outbreaks, one finds many others in the Navy where cases of this fever had been found, and often they have been in ships that were for some time in dock and where the possibility of insect infection has been marked. The question of insect infection with dengue can hardly, therefore, be put on one side. The experiments quoted recently of patients suffering from dengue in the Philippines are important ; dengue never spreads in a ward provided these patients are treated in mosquito-proof cubicles in the wards. Then another example, which has a great deal of weight in supporting the mosquito origin, is that in the time when Sir Ronald Ross had
