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TR YPA NOSOMIDM 



marrow-examined, clean dogs, whose peripheral blood and liver had 

 also been examined for parasites with negative result . The dogs be- 

 came ill and died, and the parasites were found in the bone-marrow, 

 liver, and spleen. Control dogs were then killed and found healthy. 



Basile concludes that P. serraHceps is the carrier of the disease. 

 In Bordonaro he examined i,ooo fleas from dogs and the beds of 

 families, but found only four infected with Leishmania. With 

 regard to P. irritans, Basile finds that it is frequently a parasite of 

 the dog, and that among specimens caught in the bed of a child 

 suffering from kala-azar one was found to contain Leishmania. 

 From experiments he believes that fleas are infective from December 

 to March. There is one curious point noted, that Leishmania was 

 found in spleen, liver, and bone-marrow only a few days before 

 death, though the fleas had bitten the dogs three months earlier. 



With regard to the objections to this work, Gabbi has pointed out — 



1. Canine and human fleas placed in contact with pure cultures of 



Leishmania on Nicolle's blood-agar show blood in the gut, but 

 no Leishmania. 



2. Leishmania in culture with intestinal bacteria from the flea or in 



culture with the juice from the same do not develop. 



3 . Starving fleas placed in contact with spleen-juice obtained by puncture 



from a child with kala-azar do not become infected with Leishmania. 

 Mazocchi in Piedmont finds that the fleas of dogs possess flagellate bodies 

 of a crithidia-like nature, distinct from Basile's description of the Leishmania 

 bodies found by him. 



Alvares and Pereira da Silva's experiments with Ctenocephalus sermticeps 

 support Basile, and they believe the infection to be contaminative via the 

 faeces. 



The main objection to Basile's experiments is that they were conducted in 

 Rome, in which place dogs may acquire natural canine kala-azar; secondly, 

 the question has to be solved as to whether the bodies seen in the flea are or are 

 not Leishmania, and if not, whether they are some parasite naturally occurring 

 in the flea. 



Basile describes the forms found in the flea as follows: — 

 In the mid-gut Leishmania-like forms as oval, rounded, or pyriform bodies, 

 2 to 3 ^ in length, with an excentrically-placed trophonucleus, and generally 

 a kinetonucleus. Large forms, 4 to 6 ^ by 2 to 3'5 fji, are also seen, and more 

 posteriorly pyriform bodies, 6 to 8 by 1*5 to 2*5 ^, which latter are provided 

 with flagella measuring about 3 in length.' 



Basile concludes that there is a cycle of development with preflagellate, 

 flagellate, and post-flagellate forms. But a number of fl.eas have been found 

 to possess natural parasites belonging to t\ie gQnera.He'ypetomonas and Crithidia, 

 and Miss Porter has definitely proved that Crithidia pulicis is a true parasite 

 of P. irritans. The list of known flea parasites is : — 



Crithidia pulicis Wenyon, 1908, in Xenopsylla cleopatrcB. 

 Crithidia ctenophthalmi Patton and Strickland, 1908, in Ptenophthalmus 

 (Sgyrtes. 



Crithidia hystrichopsyllcB Mackinnon, 1909, in Hystrichopsylla talpcs. 

 Crithidia pulicis Porter, 191 1, in Pulex irritans. 



Herpetomonas ctenophthalmi Mackinnon, 1909, in Ptenophthalmus tsgyrtes. 



There are also a number of unnamed flagellates recorded — e.g., a species of 

 Herpetomonas by Balfour in 1906 in Lcemopsylla cleopatrce, which may be 

 the same as Wenyon's Crithidia. It does not appear certain that Miss Porter's 

 Crithidia and Wenyon's Crithidia are the same, and if they are not, then Miss 

 Porter's Crithidia must be given a different name. 



