PRESIDENTIAL ADDRESS. | 119 
sick ones infesting his sty, or dead ones disposed of by 
being given to him to eat by keepers too lazy to destroy 
them otherwise. Whilst the possibility exists in Australia 
of the infection of man by such a route, the likelihood of 
this happening is remote, partly because skilled meat in- 
spection would probably detect the small lesions in the 
muscles of the hog, and partly because Australians are very 
particular as to cooking their supplies of meat. Some years 
ago in Perth I examined the diaphragms and other muscles 
of a small series of'rats for Trichinella spiralis, but, as 
might have been expected, with negative results. 
Gongylonema neoplasticum Fibiger et Oitlusen.—This 
worm is of interest for quite another reason. Its presence in 
the squamous celled anterior part of the digestive tract is 
associated with hypertrophy of the mucosa, which may lead 
to a papillomatous condition, and even finally to carcinoma 
(cancer), with metastatic growths in other parts. It is well 
worthy of consideration, therefore, in elucidating the vari- 
ous etiological factors that, directly or indirectly, lead to 
the onset of the cancerous process. In this case, and with 
our present knowledge, competent cancer investigators can 
come to but one conclusion, viz., that the presence of this 
worm sets up a form of chronic irritation which, like many 
other forms of chronic irritation—from a jagged tooth to 
the injuries from repeated burns and the subtle chemical 
bodies present in chimney soot—may eventually lead to the 
cell dyscrasia which is the basal change in the cancerous 
process. The intermediate hosts, from which the Black 
Rat, Norway Rat or house mouse may be infected, are the 
cockroaches, Periplaneta americana, P. orventalis and Blat- 
ta (Ectobia) germameca, and the Mealworm (Tenebrio moli- 
tor). | 
These neoplastic changes due to Gongylonema were first 
described by Fibiger? in 1918. It is interesting to note that 
2 Fibiger, quoted by Hall, Nematode Parasites of Mammals of Order 
Rodentia, etc., p. 235. 
