440 SYDNEY H. VINES. 



which he descrlhes, had been seen, but had been misinter- 

 preted by Gibelli.^ 



In the thallus of CoUetna microphyllum, Stahl detected 

 certain organs to which he gives tlie name of Carpogonia. 

 Each carpogoniam consists of a hyphal filament deeply 

 placed in the thallus, which is coiled on itself (generally 

 two or three times), and is then continued straight to the 

 free surface of the thallus, above which its terminal cell pro- 

 jects (Fig. 1). To the spirally wound portion he gives the 

 name of Ascogoniuin, to the straight portion that of 

 Trichogyne. 



Not unfrequently spermatia could be seen adhering in 

 considerable number to the projecting (Fig. 2, a) cell of the 

 trichogyne. It will be readily understood that they must 

 haye been conveyed there by means of water. In some cases 

 Stahl \vas able to detect (Fig. 2, h) a canal which placed the 

 contents of the spermatium in connection with those of the 

 terminal cell of the trichogyne. The result of this is that 

 the cells of the trichogyne wither and disappear, and that 

 certain processes of growth of the cells of the ascogonium 

 are initiated, which may be briefly described as follows : 



Tlie cells first of all increase in size, and then they undergo 

 division. As a result of this the spiral arrangement of the 

 cells becomes less and less conspicuous, for the cells gradually 

 separate from one another. Whilst these changes have been 

 taking place in the ascogonium, it has become invested by a 

 dense felt- work of hyplne formed by the active growth of 

 the hyphte of the thallus. From this investing layer hyphai 

 grow inwards between the separating coils of the ascogonium 

 and bear paraphyses, which form the rudimentary hymeniuni. 

 At the same time outgrowths have been formed from the 

 cells of the ascogonium, which either are asci or grow into 

 hyphal filaments, which bear asci as lateral branches (Fig. 3). 

 The asci, whether derived direitly or indirectly from the 

 cells of the ascogonium, come to lie in the hymenium among 

 the paraphyses. At this period of its development the apo- 

 thecium possesses all the elements which usually enter into 

 its composition. Most externally is a dense layer of interlaced 

 hyphiC forming the hypothecium, the inner portion of which 

 consists of a layer of pseudo-parenchymatous tissue, the exci- 

 pulum proprium, within this is the layer of ascogenous fila- 

 ments, and most internally lies the hymenium consisting of 

 paraphyses derived more or less directly from the hypothecium 

 and of asci derived more or less directly from the ascogonium. 



In various sp(K-ies (if Phystna, Mass. (Lempholemma, 

 ' 'Nuov-giorn. Bot. Ital.,' 1870. 



