ASCOMYCETES. 



[ 66 ] 



ASCOMYCETES. 



(fig. 40), and hence bearing a near relation 

 to the Lichens, which, indeed, are inchided 



Fig. 39. 



Fig. 40. 



Spathulea flavida. 



Fig. 39. Entire plant (reduced). 



Fig. 40, Highly magnified section of fructification, 

 showing asci and paraphyses arising from the hymenium. 



under this order by some botanists; but the 

 existence of green colouring matter in the 

 cells, and of gonidia or brood-cells, in the 

 Lichens, forbid such an association. The 

 Ascomycetes differ much in external form, and 

 approach in this particular several tribes 

 belonging to the other orders ; thus the 

 Tuberacei are very much like many of the 

 Gasteromycetes, the Helvellacei, like some 

 Hymenomycetes, &c., differing chiefly in the 

 mode of the production of the spores (figs. 

 39-42). 



Fig. 41. 



Fig. 42. 



Leotia geoglossoides. 



Fig. 41. Group of plants (reduced). 



Fig. 42. Highly magnified asci with spores. 



The Onygenei are little Fungi growing on 

 dead animal substances, feathers, horn, &c., 

 and have a flocculent mycelium, bearing little 



columnar bodies terminating in a thickened 

 head, the sporange, which is a kind of hood 

 falling off at maturity. The sporiferous struc- 

 ture, loosely filling up the hood, is composed 

 of interlacing branched filaments, bearing at 

 their free ends globular cells {asci or thecce) 

 filled with spores. The Perisporacei are like- 

 wise very simple,consisting of parasitical Fungi 

 growing upon the leaves of trees or herbaceous 

 plants. They have a flocculent mycelium, 

 often radiating from a centre, where is found 

 a membranous, sac-like, globular sporange, 

 containing sometimes a definite, sometimes 

 an indefinite number of clavate sacs or asci, 

 alone or mingled with paraphyses, and con- 

 taining ovate spores. The sporange bursts 

 either regularly or irregularly at the summit. 

 The Sphseriacei have the conceptacles more 

 developed, either single, or associated on a 

 common receptacle, and consisting of a firm 

 capsular structure, lined with asci, and open- 

 ing at the apex by a regular pore in the form 

 of a papilla or beak when mature. The 

 Phacidiacei differ chiefly in the dehiscence 

 by slits, either single and longitudinal, or 

 several and parallel or stellate, or circular so 

 as to detach a lid ; most of these have the 

 sporanges collected on a common receptacle, 

 either of horny or fleshy consistence. These 

 two tribes are but imperfectly understood, 

 since it is in this portion of the Ascomycetes 

 that Coniomycetous forms of spore are found 

 upon the same receptacle, either contempo- 

 raneously or at different stages of develop- 

 ment. Attention is directed to this subject 

 under the head of that order, and more will 

 be found under Sph^ria, Tympanis, 

 Rhytisma, Dothidea, Cordiceps, &c. 



The Tuberacei are Ascomycetous repre- 

 sentatives of the Hypogfeous Gasteromycetes, 

 being subterraneous, solid, globular or lobed 

 bodies, of fleshy consistence, the Truffle 

 being a well-known example. The organ- 

 ization of the Tuberacei is analogous in all 

 cases, but the structures differently arranged. 

 They all have an inconspicuous flocculent 

 mycelium, from which arises the solid spo- 

 range. The sporange exhibits, when cut 

 across, an outer tough coat {peridium), enclo- 

 sing a fleshy structm'e, excavated with sinuous 

 cavities giving it a marbled appearance. 

 These sinuous cavities are produced by the 

 convolutions of the spore-bearing layer, which 

 is folded and reflected backwards and 

 forwards, leaving interstices which are lined 

 with the asci or spore-sacs containing four or 

 eight spores. The degree of complexity of 

 the lacunose mass differs in different genera. 



