148 Vniversitij of California Publications in Zoology [Vol.20 



Giardia and Trichomonas present in anj' numbers in any group of 

 human eases, is Chilomasiix. 



Additional support of this conjecture is derived from the fact that 

 nearly all of the clinical writers reporting Cercomonas, such for ex- 

 ample as Guastalla (1909), MeUo Leitao (1913), Prentiss (1915), Chace 

 and Tasker (1917), and Simon (1918), have taken no note of Chilo- 

 niastix. The same is true of certain reports of larger numbers of cases 

 surveyed, as for example those of Christie (1915), 3 per cent in 100 

 natives of Sarawak, and Smithies (1918), who reports 36 eases in 

 1000 examinations in Augustana Hospital, Chicago. It is very prob- 

 able that some of the earlier clinical literatui"e reviewed by Janowski 

 (1897) reporting Cercomonas deals in reality with Chilomastix. 



2. In the second category belong certam cases of critical determina- 

 tion of flagellates in stool cultures or in stools as species of Cercomonas, 

 such as that of Wenyon (1910a) who found Cercomonas longicauda in 

 a culture from a human stool, and that of Hartmann and Chagas 

 (1910), who found C. parva n. sp. in a like culture. The first of 

 these species occurs in infusions, but neither was regarded by the 

 authors as of parasitic origin in the cultures. These investigators give 

 critical figures of the organisms and there is no doubt that they were 

 correctly refered to the genus Cercomonas. 



Less certainty as to status attends the reports of the occurrence of 

 Cercomonas hominis in the stools of dysenteric patients by Fantham 

 and Porter (1916a) and of Fantham (1916), who also later (1916ft) 

 reported two infections of C. parva in 1305 dysenteric patients in 

 England, and 3 in 14 special cases in hospitals in Liverpool. No 

 figures or accounts of the organisms thus identified are given by these 

 authors and the two reports appear to deal with the same group of 

 examinations. Porter (1918) found 10 infections by C. parva among 

 375 South African natives, but none in 10-1 autopsies, but in her account 

 details are lacking which would establish the parasitism of the 

 organisms. Woodcock (1916) reports one case of Cercomonas among 

 26 dysenteric patients at the Dardenelles. Castellani (1917) lists it 

 from the Balkans, and Sangiorgi (1919) from Italian soldiers at 

 Venice. Cutler and "Williamson (1919) li.st C. crassicauda among the 

 intestinal flagellates of man without citation of its occurrence as such. 

 Since Chilomastix was well known to these investigators and they are 

 familiar with intestinal flagellates and the literature thereof, the 

 organi.sms they have referred to Cercomonas must belong to one of 

 two genera, either to Cercomonas or to Craigia. If to the former, they 



