Ervsiphe 235 



this stage each outgrowth has much the appearance of a stem-cell 

 bearing a number of stalked spores. An interesting point in con- 

 nection with these apical outgrowths is the power they possess, 

 after the perithecium on which they occur has been detached from 

 its original substratum, of again becomin^^ mucilaijinous and so 



causing the reattachment of the perithecium to foreign objects. As 

 mentioned above, the occurrence of P. corylca on the pileus of 

 Foiucs fomcntarius is probably to be accounted for in this way, and 

 the same explanation is perhaps to be given to many of the re- 

 corded cases of the occurrence of P. corylca on herbaceous plants. 



The explanations given of the apical outgrowths by previous 

 authors have been very different. Nagcli (256) described the 

 structures as a parasitic fungus under the name o{ Schinzia pcnicUlata 

 (afterwards changed to Nacgclia pciiicillata by Rabenhorst) Bon- 

 orden (49) stated that they were part of the fungus, but that they 

 sprang from the inner wall of the perithecium and surrounded the 

 asci. Tulasne (369 and ^jo) fully described the outgrowths, and 

 placed these structures on the organic apex of the perithecium (see 

 370, tab. /). Vuillemin (379) repeated Bonorden's error of sup- 

 posing that the structures originated internally. 



Quite recently, however, Neger (258) has published a prelimi- 

 nary note on Phyllactinia^ in which the author attributes to the 

 outgrowths the function of anchoring the perithecium to the leaf; 

 the conclusion to which I had already arrived from the study of a 

 large amount of herbarium materials from all parts of the world 

 (see Journ. of Botany (314), where a more complete account of the 

 views of previous authors on the nature of the outgrowths is givenj. 

 In this article I stated that the penicillate cells spring from the 

 base of the perithecium. In a paper by Dr. Neger (Bericht. 

 Deutsch. Botan. Gescll. 17: 235-242, //. 2j, 1900) appearing 

 shortly afterwards, the author, from the study of living specimens, 

 described and figured these outgrowths as springing from the 

 apex of the perithecium. This led me 'to reexamine perithecia, 

 with the result that I found Dr. Neger s statement to be perfectly 

 correct, I can only suppose that in the section from which the 

 Fig. 6 (Journ. of Bot) was drawn, the asci were really loose, and 

 dragged round in the process of cutting. The firm attachment of 

 the perithecium by the outgrowths also led me at that time to 



