Notes and Brief Articles 



281 



several nuclei, and also that in no case are clamps to be found at 

 the cross walls. At this stage certain uninucleated cells give rise 

 to varying numbers of oidia. Miss Bensuade claims that these 

 oidia germinate. Disarticulated hyphal cells pscudoidia'') are 

 also formed which may also grow into mature mycelia. Her evi- 

 dence on this point is not at all convincing. Pure cultures from 

 isolated oidia were not made. The author further claims that 

 these oidia may fuse with a hyphal cell and thus initiate a 

 series of binucleated cells and ultimately the development of a 

 carpophore. 



The author grew spores oi Coprinus fiinetariiis inVRnTiQghQm 

 cells and succeeded in removing all but one spore so that pure 

 cultures from single spores were obtained. Ten spores were so 

 isolated, of which four developed mycelia. These showed all the 

 characteristics of primary mycelia. No persistent binucleated 

 cells were found and clamp connections did not appear at the 

 cross walls. Of these cultures, two were transferred to media 

 where it was possible to observe their growth for about eight 

 months. During this period these cultures showed no carpophore 

 development and the mycelia remained of the primary type. 

 When portions of each of these two mycelia were planted side by 

 side, thus forming a mixed culture, the secondary mycelial type 

 appeared and fruit bodies were shortly afterward formed. How- 

 ever, the author concludes that the dicaryon" does not appear 

 in monosperm cultures of C finietarius and that the binucleated 

 cells are formed following plasmogamy between cells coming 

 from two different thalli. The most common method of brine- 

 ing about these cell fusions is through the union of an oidium 

 with a hyphal cell of a different mycelium. The fact that Brefeld 

 obtained carpophores from single spore cultures of Coprinus 

 lagopus, C. stercorarius, etc., only leads Miss Bensaude to con- 

 clude that some basidiomycetes are homothallic and others 

 heterothallic, resembling in this the conditions described by 

 Blakeslee for the Mucorineae. 



The author admits that transformation of a primary into a 

 secondary mycelium is very difficult to observe, but from her 

 study of these. single spore cultures. Miss Bensaude concludes 



