THE AUSTRALIAN MUSEUM MAGAZINE. 



117 



ferinp: with tlio valvular action, allowen 

 rep:nri>-itation of the contents of the sto- 

 mach laden with plague germs into the 

 puncture. It is stated that fleas mav 

 remain infected for as long as 20 days. 



The occurrence of Bubonic plague in 

 man is thus directly consecjuent on tlie 

 presence of infected fleas and rats. If 

 there ai'e no infected rats tlie fleas are 

 harmless, if there vcvrv no fleas, in- 

 fected rats would he liarmless. The 

 flea is the direct medinni of communi- 

 cation from rat to man. 



Plague is distinctly a seasonal visi- 

 tation and the season of maximum in- 

 cidence in both rat and man corresponds 

 with the season when rat fleas are most 

 a])undant. In Sydney this falls in 

 Februai-y and March. Weekly counts 

 of the different species of fleas taken on 

 rats have been made at the DeiDartment 

 of Public Health since 1909 and these 

 show a marked increase in the numbers 

 of the Indian rat flea caught in Feb- 

 ruary and March. 



T do not propose to discuss here the 



various methods of rat and flea destruc- 

 tion, but it may not be out of place to 

 stress the necessity for every individual 

 in the community doing his or her share 

 in the campaign for the control of these 

 pests. 



The Health authorities can deal with 

 areas in which plague is known to be 

 existent, but they cannot undertake the 

 task of destrojdng the whole rat popu- 

 lation. The duty of rat destruction on 

 any jiremises must fall upon tlie owner 

 or occupier. If premises are rat-free 

 and rat-proof no anxiety need be felt, 

 but it is well to remember that any 

 faulty construction will be found out by 

 rats and full advantage taken of it. 



Cases of liuinan bubonic plague are 

 jireceded by rat plague, but too often it 

 happens that the first notification of the 

 existence of plague in a locality is re- 

 vealed only by the discovery of a human 

 case. Here the public can aid the au- 

 thorities by reporting the fact ' a.s soon 

 as any mortality is noticed among the 

 rats. 



Pigs Tusks and Armlets. 



A. R. McCuLLOCH. 



Societies for the Prevention of 

 Cruelty to Animals are strictly modern 

 outcomes of civilisation, and have no 

 counterpart among savage peoples. Pri- 

 mitive man cares nothing at all for the 

 feelings of the lower animals, and not 

 infrequently even bind.? and tortures his 

 fellow man when he feels in need of 

 some extra entertainment. Such agonies 

 as he inflicts upon his pigs in order to 

 secure their malformed tusks for his 

 personal adornment therefore cause him 

 no qualms of conscience, his only con- 

 cern being lest they damage their of- 

 fending teeth before they have reached 

 their full and painful development. 



A boar's skull is provided with a pair 

 of tusks in each jaw, which normally 

 meet in opposition, and by grinding one 

 against the other, are kept short and 

 serviceable. In order to keep them ef- 

 ficient, and to counteract their wearing. 



Nature has caused them to grow con- 

 tinuously throughout the life of the pig. 

 It follows, that, if, through any cause, 

 any one of the four tusks be not duly 

 ground away by its opj^osing fellow, it 

 will become abnormallv long; and since 



Lower jaw of a pig, with circular tusks. The 

 opposing upper tusks have been removed so that 

 the lower tusks grow without hinderance, curve 

 round and re-enter the jaw. The point of the 

 left tusk has encountered a molar tooth anJ 

 unable to grow forward has pushed the root out 

 through the side of the jawbone. 



Photo. — H. li:irnes, Junr 



