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HARDWICKE'S SCIENCE-GOSSIP. 



SPORIDtlFERA. 



Two types of structure require notice : — 



I. Physomycetes. — Sporangia containing an inde- 

 finite number of sporidia, and springing from hyphre. 



The typical forms are also known as "moulds," 

 and somewhat resemble in general appearance the 

 hyphomycetes ; but it must be borne in mind that in 

 the latter the germinating bodies terminating the 

 threads are naked spores, whereas, in the present 

 group, the vesicles are sporangia, containing sporidia, 

 which latter are the equivalent of the spore. 



II. Ascomyceies, — Asci crowded, forming a hyme- 

 nium, and containing a definite number of sporidia, 

 usually eight. 



The "mildews," whose abundant white mycelium 

 is produced on living plants, and gives origin at 

 various points to small round pustules or perithecia, 

 containing a few pear-shaped asci, includes such well- 

 known forms as those producing the hop and potato 

 disease ; the perithecia are at first yellow, then nearly 

 black, and are not furnished with an opening. 

 The asci disappear at an early stage, and the 

 sporidia are then free in the perithecia, when there is 

 a possibility of confounding them with members 

 of the physomycetes, a difficulty to be met by 

 remembering that the latter are never developed on 

 living leaves. 



The truffle may be taken as illustrating the struc- 

 ture of another group ; the species are subterranean, 

 and often of considerable size. The peridium encloses 

 a fleshy hymenium, generally very much wrinkled, 

 and marked with lines corresponding to the fruit- 

 bearing surfaces, so that the plants when cut bear no 

 little resemblance to a section of a nutmeg. 



Here again the origin of the fruit separates the 

 present from a group belonging to the sporifera, 

 with a similar habitat and general resemblance. 



In the Discomycctes the receptacle is more or less 

 succulent and fleshy, and varies much in form ; in 

 the morel it is large and pileate, whereas in the 

 genus Peziza, it is more or less cup-shaped ; the 

 hymenium is early exposed in all cases. 



The species of peziza are numerous, and vary in 

 size from three or four inches in diameter to mere 

 microscopic points ; bright colours are common in 

 this genus. 



The receptacle or cup is distinctly cellular (fig. 162I ; 

 externally it may be smooth — granular, owing to 

 projecting cells, warted, woolly, or furnished with 

 coloured septate hairs, which are generally most 

 developed near the margin. Lastly the cup may be 

 stalkless — sessile, or stipitale, furnished with a stem, 

 which may be of uniform thickness, or gradually 

 widen upwards into the receptacle. The hymenium, 

 which lines the inside of the cup, consists of asci, 

 and paraphyses closely packed side by side, their 

 free ends forming the surface of the hymenium. 



The asci vary in shape in different species, being 



cylindrical, when of uniform width, clavate, widest at 

 the summit ; they are produced in succession, and the 

 sporidia, which are produced by free cell formation in 

 their interior, escape when mature, either by an irregular 

 rupture or through a definite opening at the apex. 



The paraphyses, whose functions are not known, 

 are usually much more slender than the asci they 

 accompany, frequently septate, with the apex more 

 or less thickened, and containing granules to which 

 the colour of the hymenium is mostly due ; in some 

 species they are branched. A mucilaginous substance, 

 the Hy menial gelatine, also occurs in the hymenium. 



The remaining type illustrated by members of the 

 order Sp/neriacei, all of which agree in having the 

 hymenium enclosed in a perithecium furnished with a 

 pore, or ostiolum (fig. 161 b) at the apex, through 

 which the sporidia escape after dehiscence of the 

 asci. The perithecia are usually black, of a brittle 

 or horny texture. The hymenial gelatine is very 

 evident, and in that of Sp/ueria spennoides amorphous 

 grains of starch are present. The plants are simple 

 when the perithecia spring individually from the 

 substance on which the plant is growing ; compound, 

 when the perithecia are buried in the substance of a 

 receptacle or stroma (fig. 161, c), the surface of which 

 is usually minutely papillose, owing to the projection 

 of the ostiola. A very common plant on dead branches 

 under the form of coral or brownish-red pustules 

 {Xcctria cinnabarina) illustrates this structure. The 

 simple forms are common as minute black points on 

 dead branches, herbaceous stems, and on leaves. 



With regard to habitats, Ubiqne is the motto of 

 fungi ; a certain amount of moisture and something 

 to grow upon, and you are certain to find a repre- 

 sentative of the great fungal group in some stage or 

 other. The larger kinds that grow on the ground are 

 most abundant in woods, although some are peculiar 

 to open downs and moors, some microscopic groups 

 are confined to living leaves, and accumulations of 

 rotten wood and branches, especially when deposited 

 in damp and shady places, as the bottom of a ditch 

 or in a wood, are certain to reward a patient search. 

 When fungus hunting, don't waste the time in walking 

 from one place to another ; the mass of species can 

 only be seen when specially looked for, and hours 

 may be spent in a good locality without moving fifty 

 yards from the starting-point. The large kinds are 

 best carried in a basket, or wide vasculum, separately 

 wrapped in paper, the heaviest at the bottom, and 

 mixed with plenty of bracken fronds, which, being 

 elastic, prevent the specimens from crushing each 

 other. The leaf fungi are best placed in a book at 

 once, to prevent the leaves from shrivelling ; the 

 other small delicate kinds may be wrapped in tissue 

 paper, or, as in the case of moulds and others that 

 will not bear touching, the piece on which the plant 

 is growing should be pinned to the bottom of a cork- 

 lined box. No difficulty will be experienced in 

 drying the smaller kinds ; care must be taken not to 



