PRESIDENTIAL ADDRESS. 1h) 
drug and allied compounds in the alleviation and some- 
times cure of syphilis in man. Such treatment forms the 
essential basis in the present campaign to diminish and, if 
possible, to eliminate this scourge of mankind. Thus the 
study of a parasite of a common domestic pest has played 
a part, indirect yet by no means unimportant, in the 
diminution of human suffering. 
Tryon in Queensland was apparently the first to see this 
trypanosome in Australian rats. 
Harvey Johnston and I have found T. lewisi in EL. rattus 
and £. norvegicus in Sydney, whilst I have found them also 
in the former species in Perth, and C. J. Pound in rats in 
Brisbane.’ 
The flea Ceratophyllus fasciatus* is an intermediate host 
of 7. lewist. The flea Ctenophthalmus agyrtes and the louse, 
Hematopinus spinulosus, can also apparently transmit the 
parasites. 
HamosporipiA.—The following species have been re- 
corded * in the three rodents under consideration :—H epa- 
tozoon muris (Balfour), 1905 (1906?), in E. norvegicus 
(Africa, Oceania, Portugal, India) ; H. ratti (Adie), 1907, 
in EL. rattus (Azores, India, Oceania); H. pernicioswm Mail- 
ler, 1908, in EF. norvegicus var. albina (America); H. 
muscult (Porter), 1908, in M. musculus var. albina (Eneg- 
land) ; Piroplasma muris Fantham, 1905, in E. rattus 
var. albina (England; Nuttallia decumam Macfie, 1915, 
in HF. norvegicus (Africa) ; Toxoplasma muscula Sangior- 
gi, 1913, in M@. musculus (Italy); and 7. rattc Sangiorgi, 
1915, in H. rattus var. albina (Italy). 
Pitvon, this Journal, XO. 88s, p 3814. 
2 Vide Rep. Govt. Bur. of Microbiol. for 1909, N.S.W. (1910), p. 37. 
* Vide Nuttall, Parasitol, I., 1908, p. 296; Strickland, Brit. Med. J., 
a: eres 1049; and Minchin and Thomson, Brit. Med. J., June, 
, p. 1309. 
4 Vide Franca, Sur. la Classificat. des Heemosporidies, J. de Sci- 
encias, Matematicas, Fisicas e Naturais, 38d Serie, No. 1, 1917. 
