206 DIVISION II. COURSE OF DEVELOPMENT OF FUNGI. 



processes described in Erysiphe graminis and E. Galeopsidis, only that there the 

 resting-time begins after the formation of the asci, and the spores only have to be 

 formed when vegetation reawakens. Van Tieghem * describes a Penicillium aureum, 

 which is distinguished from P. glaucum, as regards the processes in question, 

 by having no resting-period ; he asserts, that in this species both the initial branches 

 which are spirally wound round one another are ascogenous, that is, that they both 

 send out branches, the last ramifications of which are asci. 



The sporocarps of Aspergillus (Sterigmatocystis) niger and A. purpureus 

 have, according to Van Tieghem 2 , essentially the same development and structure as 

 those of Penicillium ; and Eidam's new Sterigmatocystis nidulans, a remarkable 

 plant in many respects, should also find its place here. 



4. The sporocarps of Gymnoascus and Ctenomyces which live on animal 

 excrements usually appear, according to Baranetzky, Eidam, and Van Tieghem, 

 as small coils of felted tissue crowded together in heaps on the mycelium, the largest 

 somewhat more than i mm. high, but most of them of much smaller size. Their 

 formation commences with the union of two unicellular segments of the mycelial 

 hyphae, one of which is wound round the other in a close spiral ; the two cells arise 

 close to one another as lateral branches of one hypha, or spring from different 

 hyphae, or only the one which is wound round the other is a lateral branch and the 

 other is an intercalary member of a hypha. The member that winds round the other 

 is an archicarp or ascogonium. It ceases to grow in length when it has formed 

 a varying number of turns, and sends out branches instead, forming numerous rami- 

 fications, which are woven together into a coil and have finally at their extremities 

 round eight-spored asci like those of Eurotium. The member, round which the 

 ascogonium is coiled, and which, from the analogy of the cases previously described, 

 must be called the antheridial branch, is cylindrically club-shaped and either coiled 

 like the other cell or straight, and can no longer be distinguished by direct observation 

 when it has undergone a moderate increase in size and become divided by a few 

 transverse walls. It is not till the ascogonium begins to send out branches that the 

 young sporocarp becomes loosely enveloped by a number of hyphal branches, which 

 spring partly from the base of the ascogonium itself partly from adjacent branches of 

 the mycelium, and have their membranes thickened and coloured yellow or brick-red ; 

 the peculiar antler-like ramifications of these filaments loosely intertwined form 

 a lattice-like envelope composed of several layers round the ascogenous coil as 

 it advances to maturity. Rhizoid branches also spread over the substratum. 



5. The sporocarps of the species of Ascobolus (Fig. 95) when fully matured 

 have the typical discomycetous form. They have the form of a broad short cone, 

 the obtuse point of which is seated upon the filamentous mycelium while the broad 

 basal surface is covered by the hymenium. Their development would appear to be 

 alike in all the species ; the following account of it refers especially to Janczewski's 

 exact observation of the best-known species A. furfuraceus. The development begins 

 with the appearance of an archicarp in the form of a comparatively thick arched 

 lateral branch from a mycelial hypha; this branch becomes by successive divisions 



1 Van Tieghem in Bull. Soc. Bot. de France, XXIV (1871), p. 157. 

 3 Loc. cit. pp. 96, 203. 



