50 



ASCOMYCETELLA. 



Parasitic; receptacle thin, flattened, soft or waxy when moist, su- 

 perficial, separable; asci globose or subglobose, eight-spored; spores 

 colored when mature; paraphyses none. 



This is evidently a genus belonging to the Discomycetes, but ap- 

 parently is to be classed among the lowest forms of that division. Its 

 parasitic character and almost naked superficial asci indicate a rela- 

 tionship with the genus Ascomyces^ while the presence of a receptacle, 

 though it is but a slight one, connects it with more highly developed 

 Discomycetes. 



AscOMVCETELLA QUERCiNA: ContiUal /i^/-//^.— Hyphae tufted, 

 colorless, compound, composed of superimposed, somewhat 

 obconic masses of obovate cells placed side by side, and bearing on 

 the upper and outer margin of the masses verticels of conidia; conidia 

 oblong or subcylindrical, slightly curved, colorless, .0005 — .0006 of an 

 inch long, .00016 — ,0002 of an inch broad, produced in subelliptical 

 tufts or masses, .0005 — .0006 of an inch long and about .0005 of an 

 inch broad, each tuft composed of seven, occasionally six conidia, 

 compactly placed side by side in a circle, and forming a cylinder 

 around a central one. 



Ascigerous form, — Receptacle thin, minute, suborbicular, .01 — .02 

 of an inch in diameter, whitish or pallid; asci numerous, globose, 

 rarely obovate, .0012 — .0016 of an inch broad; spores irregularly 

 crowded, oblong, obtuse at each end, .0008 — .0009 of an inch long, 

 .0004 — .0005 of an inch broad, triseptate, some of the cells divided 

 by short longitudinal septa, at first pale or colorless, colored when 

 mature. 



Living leaves of black oak, Querctis iincioria. Union County, Ill- 

 inois. September and October. F. S. Earle. 



The conidial form of the species bears some resemblance extern- 

 ally to Microstro77ia qiiercina^ but is very differeiit in structure. Mr, 

 Earle informs me that in one instance nearly all the leaves on a tree 

 were affected by the fungus, while in another, only a few leaves. He 

 invariably finds the two forms associated together. He does not 

 think that the tree suffers any serious injury from the attacks of the 

 fungus. It was first observed by him in 1879. 



There has been sent to me also, from Maryland, a very remark- 

 able species of Polyporus, The substance of the fresh plant, when 

 cut, exudes a milky juice similar to that which, under similar circum- 

 stances, oozes from the wounds of Lactarii, The spores of this JPoly- 

 porus are also similar in size, shape and sculpture to the spores of 

 Lactarii. Inasmuch as the most obvious character of the genus 

 Lactariiis is the milky juice of the species, some may regard this 

 character in a Polyporus as sufficient to justify the formation of a 

 new genus. To me it seems unnecessary to found a new genus on a 

 single character of this kind so long as it is known to exist in but a 

 single species. When its value shall be enhanced by its known pres- 

 ence in other species, it may be well to consider the question. So 

 far as can be ascertained from the published characters of Polyporus 

 Perkeleii, Fr., our plant must resemble it externally, but no mention 

 is made of a milky juice in connection with that species; and, as such 



