382 FAMILY: TRYPAXOSOMID^ 



Chatton and liis co-workers have devoted much time and trouble to the experi- 

 mental side of this question, and though sucli a multiplicity of flagellates from a single 

 host is somewhat disconcerting, his published results are difficult to explain on any 

 other basis. Some of the flagellates have been kept in pure culture in a batch of 

 flies for over two years, and, according to Chatton, the infections have always 

 remained the same. Another, perhaps unexpected, result of his earlier work is that 

 flagellates of nearly allied species seem to be specific to their hosts. Thus, working 

 with three other species of Drosophila — viz., D. ruhrostriata, D. 'plialeraia, and I), 

 ampelophila — it was found that when bred in captivity with infected I>. confnsa 

 they did not acquire infection, though they themselves at other times are found to 

 harbour flagellates which are difficult to distinguish from those of D. confusa. The 

 flagellate of each host appeared to be specific for that host. As a result of his 

 experiments, Chatton has named two of the flagellates, which become H. rubro- 

 striatcB Chatton and Leger, 1911, and H. ampdopMlce Chatton and Leger, 1911 

 (Fig. 180). The flagellate of B. ruhrostriata remained a pure iDcritrophic infection 

 in a batch of flies from June, 1910, to March, 1911, during which time over 200 flies 

 were examined. In these flagellates, both the diphasic and monophasic forms, like 

 H. drosophilce and H. p., occurred. On the other hand, a batch of D. ampelopliila 

 bred from June to December, 1910, always showed H. ampelopMlce as an endotrophic 

 form, which corresponds to H. sp. (2) of D. confusa. 



In a later publication Chatton and Aubertot (1924) modify the view regarding 

 the specificity of the flagellate H. drosophilw ( =L. drosophilce Chatton and Alilaire, 

 1908). In B. confusa it is always endotrophic in the larva, and both endotrophic 

 and peritrophic in the adult. It has now been found that both larvfe and adults of 

 B. ruhrostriata can be infected with this flagellate. In both larvse and adults the 

 infection commences as an endotrophic one, but in the adult it may become peri- 

 trophic after a few days, owing to migration of the flagellates round the posterior 

 free end of the peritrophic membrane. It follows that the flagellate H. r\ihro- 

 striatce may be identical with H. drosophilw. 



Genus: Phytomonas Donovan, 1909. 



As explained above, the flagellates which are included in this genus 

 have only the leptomonas and leishmania forms. A very good case for 

 retaining them in the genus Leptomonas can be made, but as they occur 

 in both plants and invertebrates, and sometimes in vertebrates also, if 

 Strong's observations receive confirmation, they are conveniently placed 

 in a separate genus like the forms included in Leishmania (Fig. 181). 

 The name Phytomonas, suggested by Donovan (1909), will be employed. 



Lafont (1909) described a flagellate of the leptomonas type as occurring 

 in the latex of a plant, Euphorbia pilulifera, in the island of Mauritius. He 

 named it Leptomonas davidi, and later rediscovered the organism in two 

 other plants, E. thymifolia and E. hypericifolia. It is now known to occur 

 in various parts of the world, as the table shows (p. 390). Various species 

 of Euphorbia are involved, and it was supposed that flagellate infections 

 were limited to plants of this family till Migone (1916) described an in- 

 fection of Araujia angustifolia {Funastrum boneoriensis) in South America. 

 Migone proposed the name Leptomonas elmassiani for the flagellate of 



