ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 377 



at the apex of the cavity concealed by a dense funnel-shaped coatinf» 

 of hairs. The spores are produced eight in each ascus ; the asci 

 themselves and the periphyses deliquescing into a jelly, the swelling 

 of which forces the numerous spores out through the opening. 



If the nutriment is insufficient, small flask-shaped projections 

 are formed on the mycelium, from the swollen ends of which are 

 abstricted ellipsoidal or obovoid cells in basipetal succession ; and 

 these conidia may form balls which remain permanently attached to 

 the apex of the sterigmata ; but they, as well as those which may be 

 produced on other parts of the mycelium, appear to have lost their 

 power of germination. 



Similar results were obtained from other species ; but C. fimeti 

 has no opening to the perithecium, and C. hostrycliodes forms no 

 conidia. 



With regard to the systematic position of Chcetomium. it differs 

 from other genera of Ascomycetes, as Eurotium, Erysiphe, PenicilUum, 

 Sordaria, and Ascoholus, in the absence of any distinct differentiation 

 of the rudimentary fructification into ascogenous and enveloping 

 hyphse, agreeing on this point with Peziza Fuckeliana and Pleospora 

 herharum. Peziza is, however, a gymnocarpus Discomycete ; and 

 from Pleospora, Chcetomium differs in the perithecium originating not 

 as a tissue but as a mass of hyphse, and in the process of differentia- 

 tion of the fructification. Chcetomium must therefore be regarded, 

 like Pleospora, as a special type of Pyrenomycetes. Since the Peri- 

 sporiacese have perithecia closed on all sides and without any opening, 

 while Chcetomium resembles the Sphferiacete in having such an open- 

 ing, it is evident that the boundaiy line between the Perisporiacefe 

 and the Sphgeriacese is not so sharp as has generally been supposed. 



Zopf divides the genus into two subgenera: — (1) Euchfetomium ; 

 — perithecium with terminal tuft of hairs and an opening (C. spirale, 

 murorum, pannosum, crispatum, bostrychocles, kunzeamtm, cuniculorum, 

 indicum, and elatum) ; and (2) Chaetomidium : — perithecium without 

 any opening or terminal tuft of hairs ; furnished at its base with 

 thick wiry rhizoids {G. fimeti). Several of these species are new. 



Completoria complens, a Parasite on the Prothallium of 

 Ferns.* — This fungus has been found by Leitgeb on the prothallium 

 of Pteris cretica and other ferns, and even, in some cases, on the 

 leaves. It penetrates the host from without in the form of a spherical 

 cell, which attaches itself by a stalk-like prolongation to the outer 

 wall of the cell of the host, occupying about the centre of the cell- 

 cavity. The contents consist of finely granular protoplasm, the wall is 

 extremely delicate, and the pedicel is usually enclosed for half its 

 length in a dark-brown sheath. It then puts out a number of pro- 

 longations which penetrate the adjacent cells. The reproductive 

 cells are of two kinds, conidia and resting cells ; the formation of 

 zoospores seems probable, but has not yet been observed ; the resting 

 spores, which vary in diameter between 18 and 25 fj., are formed 

 especially when the supply of nutriment is insufficient. 



* SB. k. Akad. Wiss. Wien, Ixxxiv. (1881) (1 pi.)- See Bot. Ceufralbl., viii. 

 (1881) p. 226. 



Ser. 2.— Vol. II. 2 C 



