BY T. HARVEY JOHNSTON. 65 



Trichosoma hepatica in Mus ratfus in Lausanne and 

 mentioned that he had found it onl}^ in six out of about 

 200 rats {M. rattus and M. decumanus) examined by him 

 (1905, p. 240). In 1906 he wrote on the worm tumours 

 of the hver of the hedgehog, which he believed to be caused 

 by Tridiosoma tenue Duj., and noted the similarity to the 

 condition seen in rats (1906, p. 746). 



McCoy, Mink and Robinson* all referred to the presence 

 of Tr. hepatica in the United States. My own references 

 to the occurrences of the parasite in Australian rats and 

 mice are given in the catalogue at the end of this paper. 

 In 1916 Dr. Hall published his excellent paper on the 

 nematode parasites of rodents, etc., giving in it a short 

 account of the anatomy and life history of this worm, 

 based on published information (1916, pp. 30-33 and plate 

 1). He made the nematode the type of a new genus 

 Hepaticola, separating it from Trichosoma (or Capillaria). 



■ In 1911, Nicoll drew attention to a pathological 

 condition in the liver of an English hare, caused by a 

 Trichosoma, the appearance resembling that seen in rats. 

 Hall believed that the parasite was ])robably H. hepatica. 



The pathological condition set up has been carefully 

 described by Bancroft (1893, p. 87-8, pi. 7, fig. 7, pi. 8. 

 fig. 4) and Galli-Valerio (1903, p. 89 and text-fig. 2). The 

 tubercular or pseudo-tubercular appeai'ance is very noticeable 

 especially when the infection is heavy, and reminds one of 

 Goccidiosis. Haalandf in writing on spontaneous cancers 

 in mice mentioned that the only explanation given for the 

 chronic irritation was the jiresence of nematodes. 



A very brief summary of the life history has been 

 made by Hall (1916, p. 31). Railliet (1889), Bancroft 



*McCoy, G. Pathological conditions found in rats, etc., San Francisco. 

 Publ. Health Rep. Washington D.C., 23, (39), 1908, pp. 1366-1371. Mink, 

 0. Preliminary note on a nematode found in the liver of a wild rat. U.S. 

 Naval Med. BuU., Washington, 3(11), 1909, p. 52. Robinson, G. The rats 

 of Providence and their parasites. Amer. Journ. Puhl. Health., New York* 

 3 (8), 1913, pp. 773-77(5. These three references are quoted from Hall, 

 1916. 



tM. Haaland. Royal Soc. Loudon, IGth March, 1911. Abstract in 

 Nature, 23rd March, 1911, p. 134 

 E 



