FLAGELLATES OF DROSOPHILA 



381 



observations on the allied flagellates of D. ampelophila it would appear that these 

 small forms, still provided with flagella,, are found in the fseces, where they can 

 readily he seen. In this endotrophic parasite, which has a diphasic cycle, cyst 

 formation has so far not been discovered. 



The flagellates described by Chatton and his co-workers from D. confusa can be 

 tabulated as follows: 



1. //. rotibaudl { = L. roabandi Chatton, 1912).^Malpighian tubes of larva and 

 adult: monophasic cycle. 



2. H. SI). (1) i = T. drosophilw Chatton and Alilaire, 1908 = Bhynchoidomonas 

 drosophilw Chatton, 1913).— Larva (peritrophic), adult (Malpighian tubes): mono- 

 phasic cycle. 



3. H. drosopliilcB ( = L. drosopMlre 

 Chatton and Alilaire, 1908). — Larva 

 (endotrophic), adult (peritrophic): di- 

 IJhasic cj'cle. 



4. H. p. (=£. p. Chatton and liCger, 

 1912). — Larva (endotrophic), adult (peri- 

 trophic): monoi:>hasic cycle. It appears 

 that this may represent an alternative 

 cycle of //. drosophilce, a view which re- 

 ceives support from the later observa- 

 tions of Chatton and Aubertot (1924), 

 mentioned below. 



5. E. sp. (2) (=£. sp. Chatton and 

 Leger, 1912). — Adult (endotrophic): 

 diphasic cycle. 



As many of the tryptanosome forms 

 of insect flagellates do not appear to 

 have a well-developed membrane, the 

 axonemo running either through the 

 cytoplasm or attached directly to the 

 surface of the body, Chatton employed 

 the term lepiotnjpanosome to distinguish 

 them from the trypanosomes [eutrij- 

 panosome), which are the typical verte- 

 brate forms with a well-developed mem- 

 brane. In later writings he employed 

 the name trijpanoide for the trypanosome 

 forms of the insect flagellates. Accord- 

 ing to Chatton' s nomenclature, the series 

 of forms through which a flagellate may 



pass are these: stade monadien (leptomonas forms), which by backward migration 

 of the kinetoplast becomes the stade trypanoide (trypanosome form). 



The latter may revert to the monadien phase again. The monadien forms by 

 shrinkage of the body become the short leptomonas forms, which attach themselves 

 to the hind-gut epithelium. These Chatton terms stades gregariniens, and they by 

 migration of the kinetoplast may assume the trypanosome arrangement, when they 

 are known as stades spermoides. These latter forms become encysted. So that, in 

 the diphasic cycle of H. drosopMlce and the allied H. rubrostriatw, the following 

 stages are passed through : monadien, trypanoide, monadien, gregarinien, spermoide, 

 cyst (Fig. 178). The monophasic cycle of //. roubaudi (Fig. 176) is simpler: mona- 

 dien, gregarinien, spermoide, cyst. 



Fig. 180. — Herpetomonas ruhrostriatw 

 OF Drosophila rubrostriata ( >■ ca. 2,000). 

 (After Chatton and Leger, 1912.) 



1. Leptomonas forms (monadien). 



•2. Forms approaching the trypanosome type 

 (trypanoide), which again become 

 leptomonas forms (monadien). 



3. Retracting forms attached to cells of hind- 

 gut (gregarinien). 

 4-5. Encystment. 



