324 



PLASMODROMATA AND SARCODINA 



but was suffering from slight diarrhoea, attributed to a chill. It was 

 found in British soldiers who had been to Salonika, and in natives 

 of New Zealand serving as soldiers. In all it has been seen in seven 

 cases. 



Morphology. — It is a very small active organism, measuring when 

 rounded some 3-5-8-10-12 microns in diameter, and moving about 

 by means of extremely thin, hyaline, leaf-like pseudopodia composed 

 of sharply defined ectoplasm. The rest of the body is often rounded, 

 and consists of granular endoplasm, and is situate posterior to the 

 pseudopodia, thus giving a snail-like appearance during active 

 movement. 



The cytoplasm is alveolar and contains bacilli and cocci. There 

 is no contractile vacuole, but there are diffuse brown-stained 

 patches indicative of glycogen in iodine-stained preparations. 

 The amoeba is binucleate in about 80 per cent, of the forms ex- 

 amined, and these nuclei are usually invisible in the living organism. 

 In stained preparations they are 2 microns in diameter, and each 

 contains a large central karyosome surrounded by a clear zone, which 

 is traversed by a few very fine radiating linin threads, and which 

 separates the karyosome from the extremely delicate nuclear mem- 

 brane, on which there is no chromatin. There is sometimes a 

 separate granule to be seen lying in the centre of the karyosome, 

 which is the centriole of many authors. 



Life-History. — No signs of division or cyst formation have been 

 observed. 



Habitat. — ^The intestine of man, probably in the colon. 



Food. — Small bacteria and yeasts living in the intestinal contents. 



Pathogenicity. — It is believed to be non-pathogenic. 



Cultivation. — So far all attempts at cultivation have failed. 



Binucleate Amoebae. — We have already noted under the genus 

 Vahlkamfia two binucleate amoebae in addition to F. nana — viz., 

 V. diploidea Hartmann and Naegler, 1908, with occasional uni- 

 nucleate forms, and V . hinucleata Gruber, 1884, and have shown 

 that they probably are not Vahlkamfia and equally they are not 

 Dientamceba . Another binucleate form may be A mceba mira Glaeser , 

 1912, about which there appears to be much doubt as to whether 

 the name was given to a binucleate or uninucleate form. Schau- 

 d^rm's Par amoeba is a marine binucleate amoeba, and forms a genus 

 in which Janiclei in 1912 placed some of Grassi's parasitic amoebae 

 found in Sagitta. In these amoebae the two nuclei are dissimilar, 

 one being a nucleus and the other a Nebenkcerper. Craigia [vide 

 infra) may also possess two dissimilar bodies, one a nucleus and 

 the other like a Nebenkoerper. 



Genus Craigia Calkins, 1912. 



Definition. — Gymnamoshida, free swimming or parasitic, with a uniflagellate 

 swarm stage, and with or without an extranuclear Nebenkoerper-like body- 

 in the endoplasm. Ectoplasm seen on movement; size 10-25 niicrons. 



History. — In 1896 Schaudinn described the life- history oi Paramceha eilhardi 

 Schaudinn, 1896, which possessed a cytoplastic extranuclear body, which he 



