s 



HARDWICKE'S SCIENCE-GOSSIP. 



the mature state their threads and spores so closely 

 resemble those of the puff-balls that their vegetable 

 nature cannot be doubted. Various species of Trichia, 

 none larger than a pin's head, not unfrequently support 

 a still smaller parasite, only just visible to the unaided 

 eye, Stilbum tomeiitosum. In Stilbum there is a 

 lengthened stem formed of long threads compacted 

 together ; at the top the threads are free and form a 

 more or less round head, covered with small spores 

 which are produced from the free ends of the threads 

 forming the stem ; the spores are mixed with mucus. 

 S. tomentosum is pure white, and resembles minute 

 pins stuck into the Trichia ; the stems are connected 

 by a byssoid mycelium. Another white species, 

 S. vulgare, may be known by its habitat, decaying 

 wood, the more globose head, and absence of mycelium 

 connecting the stems. Stilbum, in common with a 

 few other genera, offers an exception to the usual 



Fig."4. — Illustrations of some of our smaller Fungi : i, Trichia 

 chrysosferma ; 2, spores and threads ; 3, Stilbum tomen- 

 tosum, natural size; 4, Stilbum tomentosum, magnified, 

 showing habit ; 5, Stilbum tomentosum, more highly mag- 



, nified. 



characters of the family Hypomycetes in having the 

 fertile threads more or less compacted to form a 

 common stem ; usually the fertile threads are free, 

 and bear the spores at their tips ; such forms are 

 known by the name of moulds, black or white, de- 

 pending on the colour of the threads. The black 

 velvety patches common on old wood and decaying 

 stems belong to Helminthosporium, one of the black 

 moulds. The species are numerous, and recognised by 

 the spreading mycelium of black or brown jointed 

 threads, from which spring similar erect ones, paler 

 upwards, and producing at the tip, rarely laterally, 

 lengthened spores, divided by a varying number of 

 septa ; these are also usually some shade of brown. 

 Another genus, equally common in similar situations, 

 might easily be confounded with the preceding until 

 examined under the microscope, when the structure 



is found to be very different ; this is Torula, belong- 

 ing to the family known as Coniomycetes, characterised 

 by the predominance of the spores over the vegetative 

 part of the plant, and almost entire absence of threads, 

 which are the great feature in the preceding family. 

 In Torula the general covering and threads are en- 

 tirely absent, and the spores are produced in straight 

 rows, looking like strings of beads. T, herbarum is 

 common on dead umbelliferous stems, forming black 

 velvety patches with a tinge of olive-green ; the chains 

 of spores are usually arranged in bundles, greenish by 

 transmitted light, the constrictions slight. The term 

 mould is too vague in its application to be of any use 

 to the student, including forms belonging to the two 

 primary divisions of fungi — those that have the spores 

 growing from spicules and not contained in a sac of 



Fig. 5. — Illustrations of some of our smaller Fungi : 1, Torula 

 lierbarum, natural size ; 2, spores, magnified ; 3, Mucor 

 fusiger and spores, both magnified ; 4, Pistillaria quisqui- 

 laris, natural size ; 5, Agaricus (Pleurotus) septicus, natural 

 size ; 6, Agaricus (Pleurotus) septicus, magnified ; 7, Typhula 

 fili/ormis, magnified. 



which all the foregoing are examples, and those in 

 which the spores are contained in a sac or ascus ; the 

 sage-green mould common on jam, bread, &c, 

 illustrates the latter section. Another species is not 

 uncommon on the gills of decaying mushrooms 

 during autumn ; the stem is very delicate, consisting o 

 a single long undivided cell ; the head globose, at first 

 white, then black and containing an indefinite number 

 of fusiform or spindle-shaped spores, which are large 

 for the size of the plant : this is Mucor fusiger ; the 

 former, in which the spores are globose, M. mucedo. 

 In Agaricus the species are generally large and often 

 brilliantly coloured ; nevertheless the subgenus Pleu- 

 rotus includes some minute and very beautiful forms, 

 recognised by the stem being lateral or absent, and 



