9 6 



DIVISION I. GENERAL MGRl'TIOLOGV. 



as it was described in Peziza Sclerotiorum, &c. (Fig. 43i> which is extended 

 by stretching into a thin membrane, it becomes a question whether the thickenings 

 in the cases we are considering arc not extended in the same way into thin membranes 

 with the expansion of the ascus, and arc to In- i on si d< red therefore as reserve-pieces 

 of membrane destined to be extended and to assist in the ejection of the spores, and 

 comparable with the ring of cellulose in the vegetative cells of GEdogonium ; the 

 matter at least deserves inquiry. 



Thickenings of the apex such as those that have been described occur also in 

 the asci of many Pyrenomycetes, in which ejection has never been observed. With 

 these may be specially mentioned the conical projection in species of Rosellinia 

 which has been recently examined by Crie* 1 , but is better understood and described 

 by de Seynes 2 . In dried specimens of Rosellinia Aquila the cone is a cylindrical ly ovoid 

 body projecting from the apex into the interior of the ascus, longer than the breadth 

 of the apex of the ascus which it almost but not quite fdls, and traversed by a narrow- 

 longitudinal canal ; in other words it is like a very thick annular ridge projecting from 

 the inner surface of the wall of the apex : it is coloured dark blue with iodine, as has 



been often described. If the view expressed 

 in the case of Cordyceps is correct, it is aques- 

 tion in the last-mentioned case also whether 

 the thickenings at the apex are not reserve- 

 pieces to assist in the ejection of the spores and 

 destined to expansion. On the other hand, 

 from Zopf's account of Sordaria Brefeldii 

 (page 88) we might ask whether they possibly 

 serve as means of fixing the spores in the apex 

 of the ascus. All this requires investigation, 

 in which each species must be separately ex- 

 amined, since ejection is by no means found 

 in all the Pyrenomycetes. 



FlG. 48. Sphturophoroi coralloides t V. rtyoin 

 b one of them more highly magnified. < a nearly ripe ascus. 

 d outline of an 

 spore from which all but a small portion of the dark violet 



, b magn. about 71 

 .:<uut 39J tin. 



Section XXVII. Liberation of the 

 spores by solution or gelatinous swelling 

 of the wall of the ascus occurs, but not 

 frequently, in fixe open hymenia. It appears, 

 however, in the latter of the two forms to 

 be characteristic of the Discomycete Roeslaria hypogaea 3 . It occurs in the first 

 form, or with a disappearance of the ascus that cannot be more exactly defined, in 

 Sphaerophoron (Fig. 48), Acroscyphus, and the Calycieae, to which the genera 

 Lichina and Paulia which have perithecia are nearly allied, as has been shown 

 by Montague 1 , Fresenius 6 , and Tulasne 6 . The young spores in an early stage 

 are almost as broad as the narrow and delicate asci, and are arranged in a 

 single or in places in a double and uninterrupted row in the upper parts of 

 the ascus. from" the wall of which they are separated by only a thin layer of 

 protoplasm (or glycogen-mass) a, b. They now enlarge mere rapidly than the 



1 Comptes rendus, SS \-->, . pp. 750. 



9 Comptes rendus, 88 (1879). pp - . .,. [043. K. Hartig in Inters. — d. furstbot. Inst. z. Miinchen 

 I, p. 20, t. II. 



 Von Thiimen, Pilze d. Weinstocks, p~ -mo. 

 4 Ann. d. sc. nat. mi. 2. XV, 1S41. 



I n senilis in Flora, i"m s . p. 753. 



Mem. p. 77. See also Strasburger, Zellbildung 11. Zelltheilung, 3rd cd. \>. =4. 



