Prof. G. de Notaris on the Tribe Sphaeriaceae. 223 



later works of Montagne, Berkeley and Corda. I shall observe 

 however that the asci present two essential modifications which 

 correspond with the characters of the nucleus. 



When the perithecium has an anhistous appearance and the 

 nucleus is amylaceous, the asci from the moment in which they 

 become visible under the microscope are found detached from the 

 walls of the perithecium and steeped, so to speak, in a sort of 

 mucous matter, in which we may frequently observe little bubbles. 

 I never succeeded in determining what relation these had to the 

 walls of the perithecium, but I am almost inclined to think that 

 the formation of the asci is repeated by a process similar to that 

 by which pollen is developed in the cavity of the anthers. All 

 species of analogous structure seem constituted of a single mem- 

 brane, which, when the inclosed sporaceous mass has scarcely 

 divided itself into sporidia, is re-absorbed or dissolved in the 

 water with which the perithecia are penetrated, and entirely dis- 

 appears. The sporidia however adhering together preserve for 

 some time their normal position, and are seen dispersed in the 

 surrounding mucous matter in groups or rows of eight which 

 retain the figure of the asci, and often show traces of a thread, 

 which, proceeding from the inferior sporidium, is lost in the mu- 

 cous matter in which the sporidia are suspended. 



The sporidia in the species belonging to the series in question 

 are very small, cylindrical in shape, mostly curved, continuous 

 or obscurely septate, transparent and of a yellowish colour, like 

 oil or pearls. Each of the sporidia frequently incloses a spori- 

 diolum of a roundish form, and which is endued with a rapid 

 motion when liberated, as may be observed if one is isolated in a 

 drop of water on the object-glass. The paraphyses are scarcely 

 to be traced at all, or are entirely wanting. 



Besides the case described, the asci, whether they spring from 

 the base of the perithecium or from the surface of its internal 

 walls, often remain adhering by their base, which is generally 

 attenuated like a peduncle, and preserve for an indefinite time 

 and even to the maturity of the sporidia their position, by which 

 the study of them is rendered much less difficult. It is easy to 

 see in them the internal membrane which lines the walls. 



In the species of this series the various forms of the sporidia 

 are innumerable; spherical, elliptic, reniform, semilunar, semi- 

 circular, lanceolate, fusiform, cylindrical, filiform, straight, curved, 

 contorted, sigmoid, didymous, simple, articulate, cellulose, po- 

 lished, facetted, torulose, provided with membranaceous appen- 

 dages, diaphanous, trapezoidal, &c. The episporium is most 

 evident in them, and sometimes equal in thickness to the endo- 

 sporium. 



When the development of the sporidia is completed, the asci 



