'-5M 



1 n/\L,jjUi-nr i tL^. 



the gleba (/); the base of the cup is continuous with the outer firm peridium. In 

 this state the spores ripen ; but for the purpose of their dissemination a great elon- 

 gation of the stem {st^ takes place ; the peridium is ruptured at the apex, the gleba 

 becomes detached from the inner peridium, this latter splitting at ^, and the mem- 

 brane t becoming detached below. The gleba is by this means raised up high above the 

 peridium on the apex of the stem, while the stem attains the height of from 6 to 12 

 inches. This elongation is brought about by the widening of its chambers, which 

 give the mature stem the appearance of a coarsely porous sponge ; it increases in 



thickness in proportion to its increase in length. 

 The spores now drop off the gleba in masses, 

 the sporiferous hyphae deliquescing into thick tena- 

 cious mucilage ; till at last nothing remains of the 

 gleba but the membrane (/) with its honeycombed 

 walls, which depends like a frill from the apex of 

 the stem, and is called the Pileus. The peculiari- 

 ties in the detail of these processes exhibit the 

 greatest variety in different species of the Phalloi- 

 deae, which may be investigated in Corda, /. f ., and 

 De Bary, I.e. p. 84. 



IV. The AscoMYCETES comprise a greater 

 variety of forms than any other order of Fungi. 

 Commencing with very simple forms comparable 

 to some unicellular Algap, as Endomyces, Saccha- 

 romyces, and Exoascus, they ascend to the truffles, 

 morells, and Sphaeriaceae with receptacles formed of 

 great masses of hyphae, the internal and external 



FIG. i78.-Longitudinal section of a nearly ripe gtrUCtUrC of which is SO VariOUS that a COmprC- 

 plant of Phallus inipudictis immediately before the ^ 



elongation of the stem (.i the natural size) ; a outer hcusivc dcSCriptioU of them is impOSSiblc. The 

 layer of the peridium; ^4> its gelatinous layer ; zinner , j^ • i- i i • i ^^ ,^ i-rr 



peridium; st the stem of the pileus/ not yet eion- commou charactcristic by which all thcsc different 



gated, covered by the white honeycomb-like ridges ; f^^^c j,_p rf>nnprf-P(i is thp n<;PVlinl formation of 



sp the dark-green mass of spores (gleba) ; h hollow lorms are connectCQ IS inc ascxuai lormaiiou or 

 cavity of the stem, filled with watery jelly ; n the cup sporcs iu thc iutcrior of sacs by frec-cell-formation. 



in which the base of the stem remains after its elon- 



gation ; x the place where the inner peridium be- ThC AsCOSpOrCS, hOWCVCr, bclOUg Only tO OUC 



comes detached by the elongation of the stem ; 7n „„„„^„4.r^„ ;„ j.i,« ^.,^1^ „r J„ „1„^„,„„4- ^C „ „„^ 



mycelial thread. generation m the cycle or development or a spe- 



cies ; for in large sections of the Ascomycetes 

 there occur in addition Stylospores of a very different nature. The course of develop- 

 ment generally shows in these cases a greater variation within a single species than 

 occurs among the Hymenomycetes ; and in many cases an alternation of generations 

 has already been recognised, in so far as the receptacles in which the ascospores are 

 produced owe their origin to a conjugation or sexual union which takes place on the 

 mycelium (as in Erysiphe, Peziza, Ascobolus, Eurotium, &c.). Want of space compels 

 me to limit my special descriptions to examples of only a few families of the order. 



(i) The simplest forms of the Ascomycetes are the Yeast-fungi or Ferments of the 

 genus Saccharorayces \ which cause the alcohohc fermentation of the saccharine juices 

 of plants (must, cider, &c.), of beer or of artificial solutions which contain sugar in 

 addition to nitrogenous substances (albuminoids or ammonia-compounds) and mineral 

 substances which form the food of plants. These Fungi consist of small roundish 

 or ellipsoidal cells, which grow in fluids, and, in nourishing themselves, cause their de- 

 composition, with formation of alcohol, carbonic acid, and other substances. Each 



^ Max Rees, Botan. Unters. iiber die Alkoholgahrungspilze. Leipzig 1870. [Compare also 

 Huxley on Yeast, Contemp. Rev. Dec. 1871 ; Pasteur, New Contributions to the Theory of Fer- 

 mentation, Comptes Rendus, 1872, pp. 784-790, and Quart. Journ. Micr. Sc. 1873, p. 351.] 



