84 
A New Saccharomycete 
first loses its regular contour, becomes sinuous, and finally breaks up into a 
mass of brownish granules... By isolating infected Daphnia, Metschnikoff 
succeeded in restoring them to health “ thanks to the destruction of the spores 
by their phagocytes. If on the other hand the phagocytic action is inadequate, 
owing to the continued increase in the number of spores swallowed or for any 
other reason, the latter begin to germinate and give rise to budding conidia.” 
Fig. I. Monosporella bicuspidata (Metsch.), after Metschnikoff, slightly schematized. 1, 2 and 3, 
budding cells; 4 and 5, elongated cells developing into asci; 6, ascus (a.) with spore (sp.); 7, ger¬ 
mination (c) of a spore ( sp .) that has penetrated into the body cavity of the host; 8, anterior 
portion of Daphnia showing the spores (sp.) of M. bicuspidata, free in the alimentary canal 
(a.c.) or perforating its wall and penetrating into the body cavity (C.c.) where they are sur¬ 
rounded by phagocytes (ph.); 9, spore (.sp.) penetrating into the body cavity, partly 
surrounded and digested by a phagocyte (ph.); 10, phagocyte containing two cells of parasite; 
11, plasmodium of phagocytes containing several cells of Monosporella; 12, fungus cell 
surrounded by two phagocytes. 
Following upon Metschnikoff, almost all authors (Zopf 1890, Hansen 1904, 
Dangeard 1907, Guillermond 1907, Lafar 1910 and Saccardo 1911) dealing 
with Monospora refer to Metschnikoff’s observation. Chatton (1907), however, 
seems to be the only author who has actually seen the parasite; thus, in his 
general account of parasites and commensals living upon Cladocera he 
mentions (p. 807) that every year during the spring he used to find Daphnia 
