444 SYDNEY H. VINES. 



affords fresli proof of the close affinity which exists between 

 these plants and tlie asconiycetous fungi. He had already 

 shown that his predecessors were mistaken in regarding the 

 pycnidia of these fungi as distinct individuals, forming the 

 genera Phoma, Diplodia, Sphaeropsis, &c., and had sug- 

 gested that, since they occur upon the mycelium with the 

 perithecia, they are probably organs of some kind belonging 

 to the fungus. De Bary's researches upon Cicinnobolus ^ 

 threw doubt upon the correctness of Tulasne's suggestion. 

 It seemed to be absolutely certain that Erysiphe and (Jicin- 

 nobolus belonged to the same mycelium, that they were in 

 jfact, different organs of the same plant : but De Bary proved 

 that this was really a case of parasitism, that the mycelium 

 of Cicinnobolus was parasitic upon that of Erysiphe. Under 

 these circumstances it was still possible to argue that the 

 pycnidia might after all be distinct fungi parasitic upon the 

 !n3celium bearing them. 



An elaborate investigation into the development of the 

 pycnidia has recently been made by Bauke'^ with the most 

 Conclusive results. Mycelia formed by the germination of 

 the ascospores of Pleospora polytriclia, Cucurhitaria elon- 

 gata, and Leptosphoeria (Pleosjjora) Doliolum, regularly 

 produced pycnidia, and the connection of the pycnidium 

 with the ascosporewas in each case satisfactorily ascertained. 

 It must, therefore, be concluded that the pycnidia do not 

 form a distinct group of fungi, but that they belong to the 

 Ascomycetes. 



These pycnidia, in the course of their development, pre- 

 sented appearances which recalled the formation of the 

 perithecium of Ascobolus and of other ascomycetous fungi. 

 In Pleospora herbarum the mode of development of the 

 pycnidium, so far as the formation of the stylospeors, is 

 essentially the same as that of the perithecium. These facts 

 suggest, as Bauke^ points out, tiiat a genetic relatio nship 

 exists between these two forms of fructification, and he goes 

 on to inquire if the pycnidia and the perithecia may not 

 be regarded as alternate generations. According to the 

 views recently propouiidi d by Pringsheim,'* as to the alter- 

 nation of generations in Thallophytes, the morphological 

 analogues of the tw^o alternate generations of Cormophytes, 

 arc to be found in the independent neutral and sexual indi- 

 ' De Bary and Worouin, ' Beit. z. Morphol. uad Pliysiol. d. Pilzc,' ill, 

 Heft, 1870. 



2 'Beilr. z. Kenutniss dor rycuiden, Nova Acta. d. k. Leop. -Carol 

 Akad.,' 187G. 



3 ' Bot. Zcitung; 1877. 



* ' Jalub. f. Wiss. Bot.,' d. xi, llcft 1, 1877 



