NEUROGLIA. 



[ 541 ] 



NIDULARIACEI. 



nerve-tubes are formed as secondary depo- 

 sits (fig. 518). 



In atrophy and degeneration of the 

 nervous elements, the nerve-cells become 

 loaded with fat and pigment, and the walls 

 of the nerve-tubes thinner, brittle, and the 

 white substance more or less replaced by 

 granules of fat. 



The nerve-fibres are very difficult of ex- 

 amination, and require a high power. They 

 may be hardened in chromic acid or Miiller's 

 liquid. Chloride of gold with the subsequent 

 addition of very dilute acetic acid, brings to 

 light the axial fibre ; while the medullary 

 sheath is darkened by osmic acid. 



BIBL. Kolliker, Mik. An. 2 ; Todd, Cycl. 

 iii. ; Gerlach, Mik. Stud. ; Remak, Monatsb. 

 Acad. Berlin, 1853 ; Schultze, Struct, nerv., 

 1868 ; Lister & Turner, Qu. Mic. Jn. I860, 

 29 ; Mayer, Strick. Hist. ; Meynert, ibid. ; 

 Deiters,* Gehirn u. Mark d. Memch., 1865 ; 

 larke, Phil. Tr. 1868 ; Beale, Phil. Tr. 1860, 

 1862, 1863,1864, Croon. Lecture 1865, Qu. 

 Mic. Jn. n. s. vols. iv. & v., & How ; Cleland, 

 Qu. Mic. Jn. 1870, 126; Darwin, Qu. Mic. 

 Jn. 1874, 110; Schmidt, M. Mic. Jn. 1864, 

 200; Frey, Hist. 624; B 3 van, M. Mic. Jn. 

 xvi. 105. " 



NEUROGLIA. A granular connective 

 tissue, with fine elastic fibres and cells sur- 

 rounding the nerve-fibres in the brain and 

 spinal cord. 



NEUROP'TERA. An order of Insects, 

 containing the Dragonflies (LIBELLULID^E). 



NEW-ZEALAND FLAX. See PHOR- 

 MTUM and TEXTILE SUBSTANCES. 



NEWT. See TRITON. 



NICOTH'OE, Aud. & Edw. A genus of 

 Crustacea, of the order Siphonostoma, and 

 family Ergasilidse. 



N. astaci (PI. 19. fig. 36, fern.) is found 

 upon the gills of the lobster. 



The sides of the body are extended into 

 two remarkable lobes, containing the ovaries 

 () and the intestinal canal. 



BIBL. Baird, Br. Ent. 300; VanBeneden, 

 Ann. Sc. Nat. 3 ser. xiii. 



NIDULARIA'CEL A small family of 

 Oasteromycetous Fungi, including the Ni- 

 dularini or bird's-nest-like Fungi, and the 

 Carpoboli, which contain only one concep- 

 tacle. They are curious and very interest- 

 ing Fungi, growing on the ground among 

 decaying sticks, dung, &c., bearing upon the 

 flocculent mycelium yellow or dull-coloured 

 fruits or receptacles (fig. 519). The ex- 

 ternal part of the receptacle consists of a 

 more or less globular or ovate peridium, 



which bursts when mature, in the Carpoboli 

 by a lid or by more or less regular slits, in 

 the Nidulariui by an orifice which enlarges 



Fig. 519. 



Fig. 520. 



Fig. 521. 



Cyathus vemicosus. 



Fig. 519. A ripe receptacle. Nat. siae. 

 Fig. 520. The same, opened vertically. 



so that the mouth becomes turned out as a 

 spreading lip around a cup-shaped cavity 

 (fig. 519). The Carpo- 

 boli, containing only 

 one conceptacle, project 

 this with elasticity 

 when ripe. The Nidu- 

 larini contain many 

 conceptacles lying like 

 eggs in a nest (figs. 

 519, 520), in Cyathus 

 and Crucibulum (fig. 

 521) attached by a funi- 

 culus. The structure 

 of the conceptacles is 

 alike in all. The en- 

 velope of each is triple 

 (fig. 522); and they 

 form a cavity lined by delicate filaments 

 which converge towards the centre, where 



Crucibulum vulgare. 



A conceptacle detached 

 from the receptacle. 



Magnified 12 diams. 



Fig. 522. 



Cyathus vernicosus. 



A nearly ripe receptacle, cut open vertically, showing 

 the two halves filled with conceptacles. 



Magnified 3 diameters. 



their extremities are expanded into lasidia 

 crowned by four spores (fig. 523), which 

 are cylindrical and almost sessile. The 

 filaments being of very unequal length, the 



