NYCTOTHERUS FABA 



205 



middle, where the oral aperture is situated. The cytopharynx is oblique and is more 

 or less curved. The cytopyge is at the posterior extremity, where a single contractile 

 vacuole is also situated. The macronucleus is almost in the centre of the parasite. 

 The members of this genus live parasitically in the intestine of amphibia, insects 

 and myriapods, and at least one species is found in man. 



Nyctotherus faba, Schaudinn, 1899. 



The body is bean-shaped, and a little flattened dorso-ventrally. 

 It is 26 /A to 28 //, long, 16 yit to 1 8 /A broad, and 10 p to 12 IJL thick 

 (fig. 116). The peristome is on the right 

 border and extends to the middle ; at 

 the left there are large adoral cilia, the 

 cilia on the right border not being larger 

 than those on the body. The cyto- 

 pharynx is short, slightly curved and 

 turned backwards. The contractile vac- 

 uole is large, spherical, situated at the 

 posterior extremity, and its contents are 

 voided through the anus at its left. The 

 macronucleus is in the centre of the body ; 

 it is globular (6 //< to 7 //, in size), and 

 contains four or five chromatin masses. 

 The micronucleus lies close to it, and is 

 spherical or somewhat elongate measuring 

 i jjb to 1*5 a (fig. 116). The cysts are oval. 



This species has hitherto only been seen once in the same patient 

 in whom Balantidium minututn was discovered. 



FIG. 1 1 6. Nyctotherus faba. P, 

 peristome ; A 7 , nucleus ; M, micro- 

 nucleus ; F~, contractile vacuole. 

 (After Schaudinn.) 



Nyctotherus giganteus, P. Krause, 1906. 



Under the name Balantidium gigafiteum n. sp., P. Krause described 

 an Infusorian which was repeatedly observed with Trichomonas intes- 

 tiinilis in the alkaline evacuations of a typhoid patient in Breslau. 

 The body is ovoid, narrower and rounded anteriorly and broader 

 and stunted posteriorly. The peristome lies to one side ; the macro- 

 nucleus is bean-shaped, the micronucleus small and globular ; one 

 or two vacuoles are present. The anus is at the farther end. The 

 organism is 90 //, to 400 //, long, 60 //, to 150 p broad (fig. 117). After a 

 prolonged stay outside the body, it becomes rounded and encystment 

 occurs. In the thermostat the Infusoria remain alive at 37 C. for five 

 weeks. 



The species, however, hardly belongs to Balaniidium, but to all 

 appearances is a Nyctoiherns and is distinguished from N . faba by the 

 difference in size. 



