208 



embryos of 0. gibsoni are found below the surface of the abdomen 

 of the host was in many instances much less than the length of the 

 proboscis of S. calcitrans. As yet all attempts to convey infection by 

 S. calcitrans have failed and no further development of the embryo 

 as been found in the fly. Of the mosquitos present on Milson Island, 

 Ochlerotatus {Culicelsa) vigilax is most abundant and is a persistent 

 biter. Failure to transmit the disease by S. calcitrans increases the 

 probability of 0. vigilax being a carrier. Future investigations might 

 be directed with advantage along the following lines : — (1) further 

 experiments with 8. calcitrans to ascertain whether wild flies in affected 

 districts can transmit embryos and whether caged flies can be artificially 

 infected and then transmit embryos ; (2) similar experiments with 

 C. vigilax ; (3) immunity experiments to ascertain whether the 

 injections of emulsions of adult worms can play any part in conferring 

 innnunity on calves. 



/S. calcitrans is abundant at Milson Island, in New South Wales, 

 Melbourne, Adelaide and Perth. Cattle and horses are the preferred 

 hosts, and attacks on man are rare. The lower parts of the legs of 

 the animals or the scrotum in bulls are chiefly attacked. The worms, 

 if injected at these points, would have to pass up the leg to the ventral 

 surface of the body, finally burrowing under the pectoral muscles and 

 the external obliques, where they may come to rest, or may migrate 

 to a more superficial position. Infestation of sheep is rare, and it 

 must be inferred that these animals possess a natural resistance to the 

 parasite. A detailed account of the examination of cattle on Milson 

 Island naturally infected with worm-nests is given. 



Elktngton (J. S. C). A Review of Recent Literature and Work on 

 the Epidemiology of Plague. — Commonwealth of Australia, Quaran- 

 tine Service, Melbourne. Service Publication no. 5, 1915. 32 pp., 

 1 map. 



Certain salient features in the world distribution of plague are 

 recorded in this paper. In India, since 1897, the disease has maintained 

 its virulence and increased its area of activity. Plague has remained 

 endemic in England for several years and the recent occurrence of 

 pneumonic cases in Suftolk on the site of previous outbreaks illustrates 

 the tenacity with which it can cling to a locality. The outbreak of 

 pneumonic plague in Manchuria in 1911 should serve to dissipate any 

 idea that plague is a disappearing disease. Australia is threatened 

 with this disease from Java, New Caledonia and Colombo. 



The practical measures of organised activity against the admission 

 and spread of plague are as follows : — (1) the collection, collation, 

 and distribution of information concerning the development of new 

 centres of infection ; (2) control and supervision of oversea shipping, 

 designed to prevent the introduction of infection from human cases 

 or infected rats ; (3) systematic fumigation on vessels for the 

 destruction or reduction of their resident rat population ; (4) organised 

 operations for the control of the rat population of towns ; (5) systematic 

 biological examination of rats and their parasites ; and (6) arrangements 

 for the notification of cases occurring on shore and for application of 

 appropriate sanitary measures. 



