
 
		u 
 tively  Elvellacei,  from  the  typical  geims  Helvella  (Plate  31,  
 fig.  4). 
 A  few  of  the  Pezizoe  are  subterranean in their  habits,  and  
 thus pave the way for  the Truffles  {Tuberacei)  (Plate 23, fig. 2),  
 which grow  completely beneath  the  surface,  answering to Hy-  
 pogæi,  p.  11,  and which  are well-known  objects of  commerce.  
 These  vary  greatly  in  structure  and  in  the  nature  of  their  
 fruit.  The more  common  have  a  rough  corrugated  surface,  
 like  the  fruit  of a Pine-apple,  but  others  arc perfectly even. 
 To  these  succeed  a  host  of  hard  or  coriaceous  species,  of  
 which  scarcely  any  attract  general  notice.  One  of  the  most  
 conspicuous is  the round,  black Fungus  {Rhytisma acerinum),  
 so  common  on  the leaves  of  different  species  of maples.  The  
 group is  distinguished  by  the  common  name  of  Phacidiacei,  
 from  the  genus  Phacidium,  of which  a  pretty  species  grows  
 on  dead  oak  and beech leaves. 
 These are  followed  by an enormous mass of plants, specimens  
 of which occur on almost every stick or stalk which we can pick  
 up in our hedges, woods, or gardens.  Some of the finest' occur  
 on insects.  Those of our own  country  are in general hut little  
 known ;  but  there  are  few  of  my  readers who  have  not  seen  
 the Caterpillar Fungus  of New  Zealand, which  is  one  of  the  
 finest in  the  section.  One  of  the  commonest  examples  is  afforded  
 by the old Sphæria Hypoxylon, which  grows  at the base  
 of stakes,  gate-posts,  etc.,  looking  like  the  snuff  of  a  candle.  
 We  have  one  or  two  larger  species,  hut  not  so  generally  
 known.  Some  recommend  themselves  to  notice  by  their  
 colour,  as  Nectria  cinnabarrina, which  is  so  common  on  old  
 sticks in gardens ;  hut  the  attraction of many consists  entirely  
 in  the  structure of  their  fruit.  The  exotic  species, which  are  
 very  abundant,  arc  often  remarkable  for  beauty  and  singularity. 
   These Fungi  are  called  Sphæriacei.  The  club-shaped 
 species  are  distinguished  from  Clavaria by their  having  their  
 fruit  contained  in  perithecia, which  are very  conspicuous  beneath  
 the  cuticle when  the plant is  divided. 
 A very  distinct  division  contains  some  of  the  productions  
 which  are  commonly known under the name of Mildew.  These  
 in  a young state  are white  and mealy,  and  are known  as Hop  
 Mildew,  Rose Mildew,  etc.;  but  as they  grow,  they form  first  
 yellow,  then  black,  speck-like  sacs, which  contain  a  different  
 form of fruit.  These sacs are attached to abundant filaments, and  
 therefore  approach  somewhat  in  appearance  to Moulds.  They  
 are  called Perisporiacei,  from  the typical  genus Perisporium. 
 There  is  yet  another  small group,  of  which one genus  consists  
 of Fungi which grow principally on  animal  substances,  as  
 decaying hoofs,  horns,  feathers,  etc.  These,  however,  arc  not  
 very  common,  and  are  therefore  little  known.  The  group  is  
 called  Onygenei,  a name  alluding to  the growth  of  one  of  the  
 species  on hoofs  of animals. 
 We have still another set of productions which rank amongst  
 Fungi,  some  of  which  are  popularly  known.  They  are  the  
 Sporangium-bearing Fungi noticed above,  p.  17.  They consist  
 of two  groups only,  the first of which  comprises the dark feltlike  
 Fungi, which run over the leaves  of living trees.  They  are  
 uncommon  in Great Britain,  and it  is probable  that  they  are,  
 in general,  conditions of other Fungi.  They  are  called Anten-  
 nariei,  from  the  threads of  some  of  them when magnified  resembling  
 the  antenna}  of  beetles.  The  other  contains  those  
 Moulds  which  have  distinct  sacs  on  their  threads,  and  not  
 naked  spores.  The  common  Moulds  of  paste  and  of  rotting  
 pears  are well-known  instances.  The  finest  British  example  
 is Mucor nitens, which grows on  fatty  substances,  and  attains  
 a considerable  size.  Most of the  species,  however,  are merely  
 microscopic objects. 
 c  3 
 Ü