104 THE ANIMAL PARASITES OF MAN 



Fantham and Porter 1 (1914-15) have shown that young mice may 

 be inoculated or fed with Herpetomonas jacnlnin, from the gut of the 

 Hemipteran, Nepa cinerea (the so-called " water-scorpion "), with fatal 

 results. The pathogenic effects are like those of kala-azar. They also 

 showed that the post-flagellate stages of the herpetomonads seemed 

 most capable of developing in the vertebrate. 



A herpetomonad, H. davidi, has been found in the latex of species of the plant- 

 genus Euphorbia in Mauritius, India, Portugal, etc. It is apparently transmitted to 

 the plants by Hemiptera. The plants sometimes suffer from " flagellosis." 



Franchini (1913) 2 has described a new parasite, Hccmocystozoon 

 brasiliense. from the blood of a man who had lived in Brazil for many 

 years. It possesses flagellate and rounded stages, and is closely allied 

 to the herpetomonads. 



Genus. Crithidia, Leger, 1902, emend. Patton, 1908. 



Crithidia is the generic name of vermiform flagellates with a 

 central nucleus, a blepharoplast or kinetic nucleus in the neighbour- 

 hood of the principal nucleus, and a rudimentary undulating mem- 

 brane bordered by a flagelltim arising from a basal granule, which is the 

 centrosome of the kinetic nucleus (fig. 49^). The anterior or flagellar 

 end of the body is attenuated and fades off as the undulating membrane. 



Crithidia fasciculate^ the type species, was found by Leger in the 

 alimentary canal of Anopheles maculipennis. Crithidia occur in bugs, 

 flies, fleas, 3 and ticks. Some of them are found in the body-fluid 

 of the invertebrate host as well as in the gut. Others may be restricted 

 to the body cavity or intestine respectively. C. melophagia from the 

 sheep-ked, Melophagns ovinns, and C. hyalommce from the haemoccelic 

 fluid of the tick, Hyalomma cegyptiuin, pass into the ovaries and eggs 

 of their hosts, and the young keds or ticks are born infected. 



C. fasciculata has been shown by Laveran and Franchini to be 

 inoculable into white mice, producing a sort of experimental leish- 

 maniasis therein. In one case cutaneous lesions were produced like 

 those of Oriental sore. 



Crithidia are natural flagellates of Arthropoda, with their own 

 pre-flagellate, flagellate and post- flagellate stages, and must not be 

 confused with transitory crithidial stages of trypanosomes. 



Genus. Leishmania, Ross, 1903. 



With an oval body containing nucleus and blepharoplast (kinetic nu- 

 cleus) but no flagellum. An intracellular parasite in the vertebrate host. 

 Included in the genus Leishmania are three species, namely : 



1 Proc. Camb. Philosoph. Soc., xviii, p. 39. 2 Bull. Soc. Path. Exot., vi, pp. 156, 333, 377. 



2 See Porter, Parasitology, iv, p. 237. 



