14 



RESEARCHES ON FUNGI 



Parasitella simplex and Chaetocladiwn Brefeldii var. macrosporum 

 and their hosts Absidia, Mucor, etc. (Figs. 5 and 6). He showed : 

 that hyphae of the parasites and hosts "attract" one another; 



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Chaetodadiu m/' 



Yig. 6.— Diagram showing in one plane stages in the union of Cluietocladium 

 Brefeldii var. macrosporum with one of its host Mucorineae {Absidia glauca, 

 Rhizopus nigricans, etc.). /, a hypha of Chaetocladium has grown toward, 

 and has applied its tip to, the side of a relatively thick host-hypha. The 

 nuclei of the parasite are shaded, and those of the host left clear. Nuclei 

 are collecting at the end of the Chaetocladium hypha. g, a septum has 

 been formed near the end of the Chaetocladium hypha ; the cell so formed 

 contains a number of Chaetocladium nuclei. These nuclei are about to 

 enlarge, and the Chaetocladium cell is about to fuse with the host-hypha. 

 h, the Chaetocladium cell has now fused with the host-hypha ; it is 

 expanding and its nuclei are growing larger, i, the Chaetocladium cell 

 (Schropfkopfzelle = cupping cell) is sending out lateral processes, its own 

 nuclei are still enlarging, and host-nuclei are wandering into it, while the 

 adjacent part of the Chaetocladium hypha is also sending out processes. 

 The Chaetocladium cell with its processes is becoming a gall (the Schropf- 

 kopf). k, the gall-cell is now larger and its branches have grown in length. 

 The Chaetocladium nuclei in the gall have now attained their maximum 

 size and are much larger than the host-nuclei. The processes from the 

 adjacent part of the Chaetocladium hypha have grown around the gall, 

 are branching, and the tip of one of the branches is causing a secondary 

 infection of the gall at s. inf. Later, Chaetocladium sporophores arise 

 from the gall and, as they form spores, completely empty it. From 

 Burgeff's Untersuchungen fiber Sexualitdt und Parasitismns bei Mucorineen. 



that a hypha of a parasite which has grown toward, and has come 

 into contact with, a host-hypha fuses with the latter ; and that a 

 curious gall, surrounded by a wall derived from the parasite but 

 containing nuclei of both host and parasite, is formed close to the 



