222 Prof. G. de Notaris on the Tribe Sphseriacese. 



not now, for want of direct observations, announce the opinion 

 I have formed. 



The perithecia in compound Spharia are found more or less 

 deeply inserted into the stroma ; in the simple species they may 

 be free or innate, isolated, fasciculate, gregarious or otherwise. 

 Their structure deserves the highest attention : the perithecium 

 in some species consists of a membranaceous, elastic, transparent, 

 reticulated sac, constituted of a single stratum of very much com- 

 pressed cellules ; in others it is made of minute, round or angular 

 cells of varied dimensions, containing a peculiar substance for 

 the most part of a fuliginous colour. The consistence, thickness, 

 fragility or tenacity depend on the greater or smaller number of 

 the cellular elements, which arranged in one or more strata con- 

 cur to form the walls, their size and reciprocal cohesion. Some- 

 times they consist of an apparently anhistous membrane similar 

 to the stratum, which by means of maceration may be separated 

 from the epidermis of the leaves of phsenogamous plants. 



If the simple Spharia presented constantly a perithecium of a 

 cellular structure, or to speak more correctly, of a stratum of con- 

 centric cells, we should think their external coat corresponded to 

 the stroma or receptacle which unites the perithecia in the com- 

 pound species; but in these as well as the others both forms 

 occur. I should rather say that the apparently anhistous peri- 

 thecium was analogous to the peridiola of the Mucedines, the 

 other to the peridia of some Gastromycetes. 



The SpJueriacecB, I remark by the way, by the symmetry of 

 their parts and their ascigerous fructification, have a great ana- 

 logy to the Discomycetes, were it not that the excipulum gene- 

 rally speaking has a filamentous instead of a cellular structure. 



The neck of the perithecium, which is highly developed both 

 in certain vertical and innate stromatic Sphm-icBj and in simple 

 species deeply buried in the matrix, does not furnish characters 

 of primary importance. The transitions from Coopertce to Cera- 

 tostomcB are notorious, and from the latter to PlatystomcBf &c. 



The asci and paraphyses, or the asci alone, constitute the nu- 

 cleus, the constant property of which in growing individuals is 

 to present the character of a gelatine of a whitish, cinereous or 

 slightly fuliginous tint. The differences depend essentially on 

 the particular state"of the asci, and the manner in which the spo- 

 ridia of these and the perithecia are set at liberty. When humi- 

 dity is wanting, the primary element in the life of Pyrenomycetes, 

 the nucleus nearly vanishes, being reduced to a sort of down or 

 to a thin crust which lines the base or cavity of the perithecia. 



Nothing can be added respecting the anatomy of the asci, spo- 

 ridia and paraphyses which has not already been registered in the 



