118 J. B. CLELAND. 
a 
is hitherto unrecorded, at least for Australia. These are 
the following :— | 
Trichinella spiralis Owen.—The ingested larve of this 
species mature in the intestines of suitable hosts. The em- 
bryos of the new generation find their way to the voluntary 
muscles. Here they encyst and develop to the infective 
larval stage. Numerous mammals may act as such hosts, 
and these include man, the pig, the Norway rat, and the 
house mouse. In man, the muscular invasion causes a severe 
typhoid-like disease, with tenderness in the affected muscles, 
which may be fatal. The presence of eosinophilia in the 
blood, due to the worm infestation, is of assistance in diag- 
nosing the illness from other similar ones. Indigenous cases 
of the disease are unknown in Australia, but Johnston and 
Cleland’ have collected the records, up to 1912, of Aus- 
tralian cases in which the infection has been derived from 
elsewhere; whilst Palmer, Cleland and Ferguson? have 
recorded a later similar case. Man is usually, perhaps 
_ always, infected by eating raw or under-done pork contain- 
ing viable larve.. The fact that both Hpymys norvegicus 
and Mus musculus are liable to infestation opens a possible 
door for the introduction of the disease eventually to Aus- 
tralia. The former, and probably the latter also, are at 
times cannibalistic. Hence the infestation of one or more 
of their number may thus spread widely to others. Their 
original infestation may be derived from eating raw pig’s 
flesh. Rats or mice may therefore be the vehicle for the 
worm’s introduction into Australia. As white people do 
not eat either of these rodents, it might be thought that 
here, as regards man, the matter ended. Unfortunately, the 
omnivorous pig is a factor to be considered. Given the 
opportunity, he would certainly eat rats or mice, either 
. 2 Johnston and Cleland, Proc. Aust. Assoc. Adv. Sc., 1912, p. 305. - 
2 Palmer, Cleland and Ferguson, Aust. Med. Gaz., June, 20th, 1914, 
p. 456. F 
