8YNCHYTKIUM. 



109 



less swollen neighbouring epidermal cells. The sporangia contain 

 reddish-yellow drops of oil, so that the swellings a})pear yellow. 

 The organs attacked are much 

 distorted and more or less 

 stunted. 



The same fungus occurs on 

 other Compositae, and is pro- 

 bably identical with S. smi- 

 f/iiineum of Schroeter, which 

 produces dark red, crusty swell- 

 ings on Cirsium palnMrc and 

 Crqjis biennis. 



Along with S. tarcuxtci one 

 often tinds Olpidium svmidans. 



S. fulgens, Schroeter (U. S. 

 America), produces reddish- 

 yellow swellings on the leaves 

 of Oenothera biennis and 0. 



, ^. l-'ic. 25.— Si/nchylriuu, f. .,..:...■,. Leaves of 



muncata ; when reSting-SpOreS Taraxamm qjndnaU so dt^fumiud by the fungus 



,, „ , , that the laminae are all more or less vindeveloped. 



appear they form brown crusts, (v. Tubeuf phot.) 



The sori of zoosporangia are 



detached from the host-plant as single sporangia, which 



become scattered over the leaves. 



S. trifolii. Pass. ( = Olpidinm trifolii, Schroeter), is as yet 

 little known. 



Other American species are : — 



S. papillatum, Farl., on Geranium. 



S. decipiens, Farl., on Am2}hicar2}aea. 



S. vaccinii, Thomas,^ on Vaccinium, Ganlthcria, K(dinia, 

 FJiododcndron, etc. 



Pycnochytrium. 



The sori of zoosporangia are not produced directly from the 

 mature sporophore, but the contents of the sporophore pass out 

 by a fine opening and form a thin- walled vesicle, the prot(jplasm 

 (tf which breaks up into sporangia. 



Schroeter divides the genus into two sul)-geuera. 



{A) Mesochytrium. The discharge of the original sporophore 



1 Halsted, " Cranberry gall-fungus " ; N. Jersey Ayr 

 18S9. With figures. 



Coll. BuUe(. 64, Dec. 



