35 



Dissemination of ascospores 



Practically all men except St^er agree that the asco- spores 

 are shot from the perithecia with great force and are thrown for a considerable 

 distance • St'ager, basirjIThis conclusions upon numerous experiments with 

 various species of Claviceps, holds tliat the ascospores are not shot sudden- 

 ly from the asci but slov>rly exude from the perithecia. He points out also 

 that ascospores cannot be carried by wind because the stroma ta are complete- 

 ly covered with a slimy layer. Daring his numerous experiments he observed 

 irany flies visiting the sphaeridia of the germinating sclerotia. Another 

 argument which, according to Stager, helps to prove that insects spread 

 ascospores ia the fact that usually the single plant on the edges of the 

 fields, T«hich are usually visited. more frequently by insects, are most 

 Cjoramonly infected with ergot. The same is true for fields lying near woods 

 vjhere the number of insects is greater. The higher humidity here may also 

 be a factor in this case, 



According to Rolfs (261) C.. Tjasiaali and C.» rolfsii asco- 

 spores are disseminated largely by beetles, mostly of the family Carabidae . 

 Engine, on the other hand, showed conclusively that when specimens Icept in 

 a moist chamber or exposed in a glass jar, are exposed for a short time to 

 sunlight and their stroma ta touched with a platinum needle, sirall clouds of 

 shining spores are discharged. These spores may be throrm for a distance 

 of about six centimeters. This tends to show that the spores do not ooze 

 -out from the ostiole of the perithecia but are shot out. Wilson (299) 

 observed that while some of the ascospores were shot out v/ith great rapidity 

 for a time from a papilla here and there, other spores exuded out gradually 

 on the surface.. Moat the cause of projection may be is only conjectured. 

 The conceptacles and the papillae seem to be filled with a brown jelly. The 



