NORTH AMKRIL'AN I'ARASITIC KXOASCE.E. 



95- 



to the Curpoifsri. and .Isro/z/yrrs bciiiL!,' such a doublful ocnus. 



it seemed to him correct to exchide it as well as the Sdcr/idr- 



oiiiyrcfcs, whose status as independent plants is still a suliject 



of controversN'. 



KXOASCE.i:. 



Aisconncetos whose ;isci ;iri.- not imitccl in a f ruftilkalion. 

 A. Those wliose asci arise as swollings in llic (.-ncls of ni\ccliuni thrcails or 

 their branches. 

 /. JiiiiJojiivc<s'\\\\a>\\^. Asci containing 4 spores, not conitiia-forining;. 

 the sterile threads forming cliianivtiospores and nionilioid conidia. 

 2. Mctffiiiis'u'lhi Sadeb. Parasitic. Asci \\ith more tlian 4 spores and 

 generalJN- conidia! formations in the asci. 

 />'. Tlie asci arise from a innunium m :)re or less loose. 



J. Ascocdrtiiiinii ]5ref. Saproph\tic on bark. The asci arise from a 

 mycelium, \vliich forms a loose hymenium. 



4. 'J'tip/iriiid Fries. Parasitic. Without perennial mycelium. A differ- 

 entiation of material occurs in the formation of tlie ascogenous 

 cells. Appearance localized. 



5. Il\o(ischs P\ickel. Parasitic. With perennial nncelium. In tlie 



formation of the asci no differentiation of mater. al. The sidi-cuti- 

 cular mycelium turns directly into the ascogenous cells. Causes 

 deformation of infected twigs. 



1 shall now make use of a translation of Professor Sade- 

 beck's generic description and classification of species, omit- 

 ting the forms that are not American and adding, in the places 

 which appear proper to me. species of whose existence he was 

 in ignorance: these are enclosed in brackets. 



A SUMMARY OF THE GENERA AND SPECIES OF 

 PARASITIC EXOASCEiE. 



EXOASCUS Fuckel. 



The continuance of the species is insured by the direct 

 infection of the spores and also bv a perennial m\'celium in 

 the host-plant; from this mycelium there develops at the time 

 of new vegetative growth, in the leaves of the infected plant. 

 a thread-like mvcelium, which spreads out in many branches 

 betw'een the cuticle and the epidermal cells, so that c[uite 

 directly, /. c. without any previous differentiation whatever, it 

 breaks up into separate pieces, while single cells or aggrega- 

 tions of several cells are set free from their connections: all 



