xc. PRESIDENT'S ADDRESS. 



whilst with special arrangements an object about half that size 

 would be seen, so that we are able to perceive creatures of very 

 minute dimensions. The King of the Belgians has offered a 

 prize of 8,000 for the discovery of a remedy for the disease I 

 have mentioned. It has not yet been awarded, though Professor 

 Koch claims to have discovered a cure in the form of atoxyl ; 

 but as the disease often lasts for years it must take a long 

 time before its efficiency can be proved. An attempt is also 

 being made to prevent the tsetse fly from becoming infected 

 with the trypanosome, which it takes in when sucking the 

 blood of an infected person and injects into a fresh victim 

 when performing the same process. To avoid this the natives 

 are being removed from the lake shore where the fly occurs, and 

 at the ports on the lake the trees which harbour it are being cut 

 down, so that it is hoped by these means to keep the plague in 

 hand and very greatly diminish it. It is sad to have to record 

 the death from sleeping sickness of Lieut. Tulloch, one of the 

 three gentlemen, sent out by the Royal Society to investigate it, 

 who have performed such excellent work. An important dis- 

 covery has been made in finding for the first time the pupae of 

 the tsetse fly in a natural position. The fly is viviparous, and its 

 larvae are not born until they are full grown, when they very 

 soon turn to a dark brown pupa about the size of a grain of 

 wheat. These had often been produced from captive flies, but 

 it has only just been discovered that pupation takes place 

 naturally in the loose earth among banana roots. As the flies 

 are abundant in some places where there are no bananas it 

 would seem probable that they also pupate elsewhere. The 

 destruction of mosquitoes {Anopheles} has been so well carried 

 out at Ismaiia that it has now become quite free from malaria, 

 though as lately as in 1902 there were 1,550 cases. This has 

 been done at an expense of something like 5,000 only, by 

 filling in and draining the pools and marsh land or treating 

 these with petroleum where the insects breed, concreting water- 

 courses, &c., and teaching the inhabitants to keep their own 

 water supplies clear of the mosquito larvae. This has been done 



