GANGLION-GLOBULES. [ 284 ] 



GASTEROMYCETES. 



quently lying on its back or side during the 

 process. Gervais distinguishes G.fluviatilis 

 from G. pulex, by the former having a dorsal 

 spine at each abdominal joint, whilst in the 

 latter this is absent. 



There are twenty-three species of Gam- 

 marus, many of them marine. Talitrus sal- 

 tator, the sand-hopper, found burrowing in 

 and hopping upon the sand of the sea-shore, 

 also belongs to the family Gammarina. 



BIBL. Desmarest, Consid. general, s. I. 

 Crustac.', M. -Edwards, Crustac. iii. ; Ger- 

 vais, Ann. des Sc. nat. 1835. 2 ser. iv.; West- 

 wood, Phil. Trans. 1835. 



GANGLION - GLOBULES, or NERVE- 

 CELLS. See NERVES. 



GASTEROMYCETES. An order of 

 Fungi, characterized by the production of 

 their free spores upon basidia seated on a 

 sporiferous structure forming convolutions 

 in the interior of an excavated fruit, which 

 ultimately bursts to allow the sporiferous 

 structure to expand and scatter its spores. 

 The fruit of the Gasteromycetes is ordinarily a 

 globular, elliptical, or shapeless mass, varying 

 in size from microscopic minuteness to the 

 dimensions of large leather balls, often 

 stalked, arising from an inconspicuous floc- 

 culent mycelium. This external body con- 

 sists of a leathery or membranous, simple or 

 double sac (peridium}, which bursts in va- 

 rious ways at maturity. When examined 

 young, these Fungi appear solid; but as they 

 advance, various structures become gradu- 

 ally marked out in their interior, and appear 

 more and more distinct until mature. 



IntheNidulariacei little concept acles are de- 

 veloped in the interior of the sac-like peridium ; 

 and when the latter is mature, it opens like 

 a cup or vase at its summit, exhibiting the 

 conceptacles within, lying like eggs in a nest. 

 These conceptacles are hollow, and lined 

 with basidia bearing free spores. The Myxo- 

 gastres are minute Fungi growing upon 

 wood, leaves, &c., and looking at first to the 

 naked eye like patches of froth. They are 

 stated by authors to offer originally no trace 

 of organization, but to present, after a time, 

 floating spores, the mucilaginous mass finally 

 drying and dividing into a number of con- 

 ceptacles. This account is evidently crude 

 and imperfect, the mycelium threads being 

 overlooked. At certain stages, however, the 

 conceptacles do appear imbedded in mucila- 

 ginous matter, cementing them more or less 

 together, and they become free and isolated 

 after the mucilage has dried up. At matu- 

 rity, the conceptacles, which are sacs, and con- 



sist of a double peridium, burst and emit the 

 sporiferous structure, which often rises from 

 the conceptacle and expands in various forms. 

 The sporiferous structure is called the capil- 

 litium, and consists of a collection of simple 

 or anastomosing filaments, either attached 

 to the peridium, and forming a kind of net- 

 work, from between the meshes of which 

 (probably the seat of their development) the 

 spores fall out ; or free and discharged with 

 the spores. The free filaments of several 

 genera are marked with striae, which in 

 TRICHIA may be clearly seen to arise from 

 a spiral fibrous structure like that of the 

 elaters of the Hepaticacese. 



The Trichogastres exhibit in most cases 

 the appearance of a leather ball, arising from 

 an inconspicuous flocculent mycelium, but in 

 Broomeia the sporanges are imbedded in 

 large numbers in a common fleshy matrix. 

 The internal structure differs to a consider- 

 able extent in its earlier stages. The peri- 

 dium is either single or double, the inner 

 being often quite free, and becoming everted 

 at the time of dehiscence. The interior of 

 Polysaccum (fig. 271) and Scleroderma (fig. 

 274) consists in the early state of a mass of 

 structure formed by the production of the pe- 

 ridium, in the form of septa, in all directions 

 into the interior, so as to divide it into cham- 

 bers, each of which contains a nucleus of 



Fig. 271. 



Fig. 272. 



Polysaccum crassipes. 

 Fig. 271. Natural size. 

 Fig. 272. Section from ditto, showing the loculi. 



filamentous, cellular substance, or concepta- 

 cle, hollow in the centre, into which project 

 the ends of the filaments, bearing basidia 

 with two to six spores. At the epoch of 

 maturity all the internal structure has va- 

 nished, except the spores and detached par- 

 ticles of the filaments on which they were 

 developed, and these escape on the bursting 



