Fungi, Ascomycetes, Ustilaginales, Uredinales . Fig. 19. Ereinascus fertilis Stoppel; stages in the formation of the ascus, both by fusion of twocells and parthenogenetically; after Fig. 10. Endomy , Magnusii Ludw.; a. i. antheridium and oogonium in contact; c. oogonium afterfusion of sexual nuclei; d. parthenogenetic ascus; Endomyces filniligtr Lindner; e. conjugationbetween two neighbouring cells, al the end of the hypha is a group of young asci; /. normal andparthenogenetic asci; after Guilliermond. 6o PLECTOMYCETES [CH. themselves multiply by budding. Under appropriate condi
Fungi, Ascomycetes, Ustilaginales, Uredinales . Fig. 19. Ereinascus fertilis Stoppel; stages in the formation of the ascus, both by fusion of twocells and parthenogenetically; after Fig. 10. Endomy , Magnusii Ludw.; a. i. antheridium and oogonium in contact; c. oogonium afterfusion of sexual nuclei; d. parthenogenetic ascus; Endomyces filniligtr Lindner; e. conjugationbetween two neighbouring cells, al the end of the hypha is a group of young asci; /. normal andparthenogenetic asci; after Guilliermond. 6o PLECTOMYCETES [CH. themselves multiply by budding. Under appropriate conditions the myceliumalso bears naked, four-spored asci, the development of which has beenstudied by Guilliermond. In Endomyces Magnnsii vegetative multiplication is by the separationof oidia cut off by transverse walls. The ascus is the product of a definitesexual process in which an elongated, swollen cell and a relatively narrowone grow up, bend towards one another and unite. The single nucleus ofthe smaller cell passes into the larger and fuses with its nucleus. Two karyo-kinetic divisions take place, so that four nuclei and ultimately four sporesare produced (fig. 20). Fusion appears to
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectfungi, bookyear1922
