CHYTRIDIALES 497 



Chytridium sphaerocarpum Dangeard 



Le Botaniste, 2: 244, pi. 17, fig. 9. 1890-91 



(Fig. 31 B, p. 496) 



Sporangium sessile, narrowly or occasionally broadly pyriform, usu- 

 ally asymmetrical, 8-18 ;jl long by 7-8 \i in diameter, with a prom- 

 inent apical papilla surmounted by a very inconspicuous thin-walled 

 convex operculum 3-5 \x in diameter, wall thin, smooth, colorless; 

 rhizoidal system of varying length, consisting of an extremely tenuous 

 long stalk which forms at its tip a few branches or remains unbranched; 



Explanation of Figure 31 



A. Chytridium olla Braun on oogonium of Oedogonium, two discharged 

 sporangia. B. Chytridium sphaerocarpum Dangeard on hypha of Achlya. C. 

 Chytridium perniciosum Sparrow on Navicula, two discharged sporangia on 

 portion of diatom. D. Chytridium papillatum Sparrow on Stigeoclonium, 

 immature and discharged sporangia on portion of algal filament. E. Chytrid- 

 ium versatile Scherffel on moving Navicula; to the left, five encysted zoospores 

 and a mature sporangium on its flexible stalk; to the right, a discharging 

 sporangium. F. Chytridium appressum Sparrow on Melosira, habit of a ma- 

 ture sporangium. G. Chytridium curvatum Sparrow on sheath of Stigeoclo- 

 nium. H. Chytridium nodulosum Sparrow, on Melosira, three sporangia, the 

 one in upper right showing characteristic protuberance (zoospore case?). /. 

 Chytridium inflation Sparrow on Cladophora, discharging apophysate spo- 

 rangium. J. Chytridium confervae (Wille) Minden, immature sporangium on 

 Tribonema. K. Chytridium aggregatum Karling on Cladophora, single apoph- 

 ysate sporangium from a group; persistent amber-colored case of zoospore 

 appears as protuberance on left side of sporangium wall. L-M. Chytridium 

 lagenaria Schenk on Rhizoclonium and Oedogonium: L, empty apophysate 

 sporangium; M, germinating resting spore on Oedogonium; endobiotic rest- 

 ing spore has produced a germ tube, which has pierced wall of alga and form- 

 ed at its tip, epibiotically, a zoosporangium. N-P. Chytridium polysiphoniae 

 Cohn on the seaweeds Polysiphonia and Ceramium: N, mature sporangium 

 on Ceramium; O, discharging sporangium on Polysiphonia; P, discharging 

 sporangium on Ceramium. Q. Chytridium megastomum Sparrow, empty spo- 

 rangium on hairs of the brown seaweed Striaria. R. Zygorhizidium willei 

 Lowenthal on Cylindrocystis, empty sporangium, showing small endobiotic 

 apophysis and once-branched rhizoid. 



(A, Braun, 1856a; B, Sparrow, 1936a; C-D, Sparrow, 1933c; E-l, Sparrow, 

 1933a; L, Sparrow, 1936a; M, Karling, 1936a; N, Sparrow, 1934c; O, Spar- 

 row, 1936b; P-Q, Sparrow, 1934c; R, Lowenthal, 1905) 



