Septembar  4,  1902. 
JOURNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER. 
217 
Australia  and  South  Africa  there  is  no  verdant  landscape  or  dairy 
farming  scenery,  and  “  a  farm  ”  is  the  last  place  at  which  to 
procure  the  aforesaid  necessaries  of  European  life.  These  things 
are  only  developed  within  easy  distance  of  the  most  populous  dis¬ 
tricts — one  of  which  the  Rand  is  certain  to  become.] 
An  Evening  with  the  Microscope. 
(Concluded  from  par/e  203.) 
The  most  interesting  members  of  the  class  Arachnid*,  and 
well-known  to  all  of  us,  are  the  common  red  spider  which 
infests  our  plants,  and  also  the  cheese  mite,  both  of  which, 
when  viewed  under  the  microscope,  have  the  appearance  of  great 
beetles  marching  about.  A.s  regards  the  parasites  of  birds, 
animals  and  human  beings,  it  is  a  most  remarkable  fact  that 
those  of  nearly  every  genera  differ  in  size,  although  they  are 
practically  the  same  in  formation.  For  instance  there  are  the 
large  and  small  fleas;  the  large  and  small  lice,  &c.  Let  us  take 
the  acari  of  the  linnet,  humming  bird,  swallow,  starling,  ferret, 
goose  or  hare;  the  parasite  of  the  rat,  red  deer,  hornbill,  horse, 
pig;  the  flea  of  the  cat,  dog,  pig,  fowl,  human  being,  all  much 
resemble  each  other  in  their  respective  genera,  and  existing  as 
males  and  females.  As  regards  the  parasites  of  human  beings, 
probably  the  most  common  and  the  least  known  is  the  Demodex 
folliculorum  that  infests  the  follicles  of  the  skin,  more  particu¬ 
larly  the  nose,  and  few  people  are  without  them.  You  have 
seen  dark  and  mattery  spots  on  the  nose,  and  people  squeeze 
them  up  with  their  fingers  and  out  comes  a  little  matter  which 
contains  the  demodex,  a  very  minute  insect,  but  under  high 
powers  of  the  microscope  it  has  the  appearance  of  a  long  very 
thin  kidney  Potato,  or  very  thick  worm,  with  four  legs  on  each 
side  of  the  upper  portion  of  the  body.  It  is  figured  in  Messrs. 
Beck’s  book  on  the  Microscope,  magnified  tfOO  linear,  also 
in  the  Micrographic  Dictionary,  and  we  are  told  by  a  highly 
experienced  man  that  one  of  the  varieties  of  mange  in  dogs  is 
caused  by  the  Demodex  folliculorum,  and  that  no  permanent 
cure  is  known,  while  the  parasite  that  causes  mange  in  the  horse 
is  of  a  totally  different  character,  and  very  much  resembles  the 
cheese  mite. 
Waldsteinia  trifolia.  (Sec  page  218. ; 
One  of  the  most  dreaded  parasites  to  cattle  is  the  gad-fly 
(Tabanus).  They  deposit  their  eggs  by  means  of  their  oviposi¬ 
tors,  under  the  skin  of  animals,  where  they  remain  to  hatch 
out,  and  are  for  some  time  very  troublesome.  Animals  so  in¬ 
fested  are  easily  detected  by  swollen  lumps,  generally  on  their 
backs  and  sides.  The  eggs,  larvae,  and  portions  of  this  insect 
are  very  interesting  microscopic  subjects. 
Hydra  cr  fresh  water  polypes  are  also  most  interesting 
microscopic  subjects.  They  are  to  fresh  water  insects  what  the 
octopus  and  Physalia  pelagrica,  or  Portuguese  man-of-war,  is  to 
living  beings  in  the  sea.  They  are  of  most  remarkable  construc¬ 
tion,  and  common  in  almost  every  pond  of  fresh  water.  There 
are  four  or  five  British  species.  When  contracted  they  appear 
like  balls  of  jelly,  about  six-tenths  of  an  inch  in  diameter,  and 
are  found  adhering  to>  sticks  that  may  be  in  the  water,  stones, 
leaf  stems,  &c.  ;  in  fact,  they  attach  themselves  to  any  substance 
by  means  of  their  tails.  They  have  a  body,  a  number  of  ten¬ 
tacles  or  feelers,  a  mouth,  but  no  eyes.  They  throw  out  their 
feelers  or  tentacles  into  the  water,  and  the  moment  a  water 
mite,  insect,  or  worm  touches  them,  they  are  instantly  seized, 
drawn  up  into  the  stomach,  and  all  nutriment  sucked  out  of 
them.  The  victim  is  then  disgorged,  and  if  there  is  any  portion 
left  that  the  stomach  could  not  hold,  the  remainder  is  treated 
in  the  same  way. 
Doubtless  our  best  authority  on  this  subject  was  the  late  Henry 
Baker,  Esq.,  F.R.S.,  who  made  long  experiments  with  them,  and 
published  the  results  in  book  form  in  1743,  being  a  series  of 
letters  of  his  experience  to  Martin  Foulkes,  Esq.,  then  President 
of  the  Royal  Society.  There  are  many  illustrations  of  them  in 
his  work,  some  showing  the  captured  worm.  Again,  in  Quekett’s 
Lectures,  and  in  Mantell’s  “Invisible  World,”  published  in  1850, 
there  is  a  coloured  illustration  showing  the  worm  captured,  and 
also  in  the  stomach  of  the  animal.  As  regards  the  numerous 
water  fleas  and  fresh  water  mites,  these  are  remarkably  interest¬ 
ing  when  viewed  alive  in  water  in  the  zoophyte  trough. 
Spicules  of  sponges  and  gorgonias,  sections  of  the  spines  of 
Echinus  (Sea-urchin),  spatangus  (Heart -urchin  or  Sea-bun),  liolo- 
thuria-  (sea-  cucumber),  ophiocorna  rosula  (British  star  fish), 
young  oysters,  foraminifera.  and  Polycistma  are  all  remarkably 
beautiful  subjects  for  the  microscope. 
Micro-photographs  also  claim  a  share  of  attention,  whether 
they  are  copies  of  Scripture  extracts,  pictures,  or  views  of 
various  parts  of  the  country.  For  instance,  just  picture  to 
yourself  Sir  Walter  Scott’s  monument  in  Edinburgh,  or  the 
Pagoda  and  fountain  at  Alton  Towers  being  mounted  on  slides, 
the  subjects  themselves  not  being  larger  than  the  head  of  a  pin, 
and  quite  indiscernible  to  the  naked  eye. 
Of  minerals  I  have  a  good  collection,  and  it  would  puzzle 
me  to  say  which  are  the  most  beautiful  and  interesting — those 
mounted  as  opaque  objects,  or  those  for  transparent  and 
polarised  light.  As  regards  polarised  light  there  are  a  great 
many  subjects  mounted  for  this  purpose — animal,  vegetable, 
mineral,  chemical,  and  crystals.  Probably  none  are  more 
beautiful  than  a  section  of  the  horn  of  a  rhinoceros,  the  tendon 
of  an  ostrich,  crvstals  of  sulphate  of  copper  and  magnesia,  or 
crystalised  salicine  ;  but  there  are  abundance  of  them  equally 
beautiful. 
As  regards  anatomy  (human  and  animal),  pathology,  histo¬ 
logy,  morbid  and  other  diseases,  I  have  a  collection  of  over  1,000 
slides  on  these  subjects,  and  6,000  slides  in  all,  I  think  sufficient 
has  now  been  said,  although,  if  time  would  allow,  some  of  these 
are  most  beautiful  and  full  of  interest.  As  in  all  other.brancbes 
of  study,  it  is  very  necessary  to  have  some  good  books  on  the 
subject  to  refer  to.  I  have  found  the  following  very  useful  from 
which  to  gather  information  which  I  possess,  viz. : — • 
I.indley’s  School  Botany 
Lindlev’s  Vegetable  Kingdom 
The  Treasury  of  Botauy,  2  vols.,  by  ; 
Bindley  and  Moore 
Withering’s  British  Plants,  condensed 
by  Macgillivrny 
Hooker’s  British  Flora 
The  Microscope,  1  v  Lnrilner 
The  Achromatic  Microscope,  by  Beck  j 
Microscopic  science,  2  vol*. .  by  Cole 
The  Microscope,  by  Ur.  Carpenter 
The  Microscope,  by  Dr.  Carpenter, 
edited  hv  Ballinger,  last  edition 
Microscopic  Anatomy  of  the  Human 
Body,  i  vols.,  by  Hassell 
The  Invisible  Woild,  by  Mantell 
Mierooraphic  Dictionary,  by  Griffith 
and  Htnfrey 
Outline  j  of  Practical  History,  by  Stir-  j 
ling  . 
Klements  of  Histology,  by  Klein 
History  of  Polype*,  by  Baker 
Textbook  of  the  Microscope,  by  Griffith 
Spectrum  Analysis,  by  Roscqe 
Spectrum  Analysis,  by  Scheliens 
British  Zoophytes  or  Corallines,  by 
Landsborough 
Manual  of  Zoology,  by  Nicholson 
Infusoria  (Diatomacese  and  Desmi- 
daeeah,  by  Pritchaid 
Microscopic  Fungus  (Rust,  Insect, 
Mildew,  and  Mould),  by  Cooke 
The  Insect  World,  by  Figuier 
A  Natu’alisFs  Voyage  Round  the 
World,  by  Charles  Darwin 
British  Sea-Anemones  and  Corals,  by 
(ioaSd 
The  Annual  of  Micros, opy 
Queckett’s  Lectures 
Manual  of  Injurious  Insects,  by 
Ormerod 
Cassell’s  Natural  History,  C  vols. 
Voyage  of  the  Challenger,  by  Sir 
Wyville  Thomson,  2  rols. 
&c. ,  &c. 
*  Paper  read  by  Mr.  J.  Ollerhead  at  a  meeting  of  the  Wimbledon  and 
District  Gardene-s’  Mutual  Improvement  Society,  February  17th,  1902,  the 
subject  being  again  brought  forward  o:i  March  17th,  after  a  discussion  on 
Roses  n  pots. 
