Comment: Hertig {loc. cit.) regarded this species as possibly related to Rickettsia lectularia Arkwright et al. Philip (Canad. Jour. Microbiol., 2, 1956, 266), however, regards these two species as more logically placed in different genera. Pathogenicity and source: This species is described in the role of a harmless parasite which causes some degeneration of parasi- tized gonad cells of the mosquito host, Culex pipiens; studied in mosquitoes of North America and China. It is passed through the eggs of the host to succeeding generations. 2. Wolbachia culicis (Brumpt, 1938) Philip, 1956. (Rickettsia culicis Brumpt, Ann. Parasitol. Hum. et Comp., 16, 1938, 153; Philip, Canad. Jour. Microbiol., 2, 1956, 267.) cu.li'cis. M.L. noun Culex a genus of mosquitoes; M.L. gen. noun culicis of Culex. Small, pleomorphic, intracellular organ- isms. Stained in sections with haemalum, and with erythrosine-orange and toluidine- blue. Gram-negative. Cultivation: No attempts reported. Pathogenicity and source: Found in the epithelial lining of the stomach of mos- quitoes (Culex fatigans), where destruction of the cells of the hind gut occurs. Differ- entiation from W. pipientis Hertig is pre- sumably on the basis of this pathogenicitj^ though it remains to be proved that this is not a strain difference. Brumpt postulated that parasitism of man might occur since the original mosquitoes had been fed on filaria-carrying persons. 3. Wolbachia ctenocephali (Sikora, 1918) Philip, 1956. (Rickettsia ctenocephali Sikora, Arch. f. Schiffs- u. Tropen-Hyg., 22, 1918, 445; Philip, Canad. Jour. Microbiol., 2, 1956, 267.) cte.no.ce'pha.li. M.L. mas.n. Ctenocepha- lus (now Ctenocephalides) a genus of fleas; M.L. gen. noun ctenocephali of Ctenocephalus. Organisms of two sizes were observed by Sikora, the larger resembling Rickettsia pediculi and the smaller, Rickettsia melo- phagi. Vary from minute cocci, 0.3 to 0.4 micron in diameter, to rather large, swol. len, curved rods, 0.3 by 1.5 to 2.0 microns- Stain reddish with Giemsa's stain. Bipolar staining observed in some rods. Gram- negative. Cultivation: Not reported, though propa- gation in the coelomic fluid of the body louse is claimed. Comment: Regarded by Macchiavello (Prim. Reunion Interamer. del Tifo, Me.xico, 1947, 418) as a variety of his later described Cowdryia pulex. Pathogenicity and source: Found on the surface of organs in the body cavity and in the coelomic fluid of cat fleas (presumably Ctenocephalides felis) where no particular damage was reported. 4. Wolbachia pulex (Macchiavello, 1947) Philip, 1956. (Cowdryia pidex Macchiavello, Prim. Reunion Interamer. del Tifo, Mexico, 1947, 418; Philip, Canad. Jour. Microbiol., 2, 1956, 267.) pu'lex. M.L. noun Pulex a genus of fleas. Described as rickettsioid organisms and as tj^pical rickettsias which, in fleas, can be confused with bacteria, especially those of the intestine. Macchiavello 's stain serves to differentiate these organisms. Presumably stain red by Macchiavello's method. Cultivation: Not attempted. Pathogenicity and source: Non-patho- genic for the host fleas. Hundreds of inocula, consisting of batches of fleas, when injected into guinea pigs caused, in two instances, symptomatic responses. However, in neither case could this organism be related to the response nor could Rickettsia typhi be elim- inated as a potential excitant. 5. Wolbachia trichodectae (Hindle, 1921) Philip, 1956. (Rickettsia trichodectae Hindle, Parasitology, IS, 1921, 152; Philip, Canad. Jour. Microbiol., 2, 1956, 267.) tri.cho.dec'tae. M.L. fem.n. Trichodectes a genus of biting lice; M.L. gen. noun trichodectae of Trichodectes. Rickettsia-like, extracellular, minute coc- coid and rod-shaped organisms resembling Wolbachia melophagi in morphology, aver- aging 0.3 to 0.5 by 0.5 to 0.9 micron. Stain purple with Giemsa's stain. Cultivation: Not reported. Source: Found in 7 to 8 per cent of biting lice (Trichodectes pilosus) where it propa-
