﻿189^-] 
  BOTANICAL 
  GAZETTE. 
  169 
  

  

  of 
  preservative 
  substances 
  in 
  water, 
  and 
  with 
  the 
  

   fungi 
  by 
  the 
  use 
  of 
  ghcerine, 
  usually 
  diluted 
  with 
  sonue 
  

   antiseptic 
  fluid 
  or 
  solution 
  of 
  low 
  density. 
  But 
  all 
  such 
  

   media 
  are 
  permanent!}' 
  fluid 
  and 
  require 
  'the 
  use 
  of 
  arti- 
  

   ficial 
  cells 
  .to 
  contain 
  them. 
  These 
  cells 
  when 
  not 
  

   built 
  wholl}'^ 
  of 
  some 
  cement 
  depend 
  on 
  such 
  a 
  ma- 
  

   terial 
  for 
  their 
  security, 
  and 
  require 
  to 
  be 
  made 
  with 
  

   the 
  greatest 
  care 
  and 
  to 
  be 
  freshlj' 
  coated 
  at 
  intervals. 
  

   After 
  a 
  considerable 
  experience 
  with 
  nearly 
  all 
  the 
  best 
  ce- 
  

   ments, 
  I 
  am 
  convinced 
  that 
  none 
  is 
  wholly 
  "^to 
  be 
  relied 
  on, 
  

   while 
  the 
  trouble 
  of 
  manipulating 
  them 
  and 
  of 
  preparing 
  

   satisfactory 
  mounts 
  in 
  fluid 
  makes 
  the 
  abandonment 
  of 
  the 
  

   whole 
  technique 
  extremely 
  desirable. 
  Further, 
  veiy 
  few 
  of 
  

   the 
  liquids 
  in 
  use 
  preserve 
  delicate 
  histological 
  features 
  or 
  

   differential 
  staining. 
  

  

  About 
  the 
  only 
  available 
  non-resinous 
  solid 
  medium 
  is 
  giy- 
  

   cerine 
  jelly 
  which 
  has 
  proved 
  so 
  entirely 
  applicable 
  and 
  so 
  

   well 
  adapted 
  to 
  the 
  preservation 
  of 
  a'lga; 
  and 
  fungi 
  that 
  

   fluid 
  media 
  and 
  cements, 
  which 
  have 
  been 
  used 
  chiefly 
  for 
  

   these 
  plants, 
  may 
  be 
  now 
  relegated 
  to 
  the 
  limbo 
  of 
  super- 
  

   seded 
  evils. 
  

  

  The 
  object 
  of 
  the 
  present 
  note 
  is 
  to 
  call 
  the 
  attention 
  of 
  

   American 
  botanists 
  to 
  a 
  mode 
  of 
  treatment 
  preliminary 
  to 
  

   mounting 
  in 
  glycerine 
  jelly, 
  which 
  is 
  not 
  complicated 
  in 
  de- 
  

   tail, 
  is 
  very 
  satisfactory 
  in 
  its 
  results, 
  and 
  is 
  widely 
  applica- 
  

   ble 
  among 
  the 
  thallophytes. 
  In 
  Iledwlgla 
  for 
  1888, 
  Heft 
  5 
  

   and 
  6, 
  page 
  121, 
  Dr. 
  L. 
  Klein 
  described 
  his 
  method 
  of 
  pre- 
  

   paring 
  slides 
  of 
  fresh-water 
  alga?, 
  which 
  the 
  writer 
  has 
  found 
  

   verv 
  successful 
  and 
  convenient. 
  

  

  . 
  ihe 
  prime 
  secret 
  of 
  success 
  in 
  the 
  use 
  of 
  glycerine 
  jelly 
  

   js 
  to 
  have 
  the 
  object 
  thoroughlv 
  permeated 
  by 
  glycerine 
  be- 
  

   fore 
  it 
  38 
  placed 
  "in 
  the 
  medium". 
  But 
  the 
  well-known 
  dehy- 
  

   arating 
  action 
  of 
  glycerine 
  causes 
  a 
  rapid 
  and 
  irreparable 
  

   shrinking 
  and 
  collapse 
  of 
  delicate 
  watery 
  tissues 
  placed 
  in 
  it, 
  

   ^ven 
  though 
  it 
  be 
  very 
  much 
  diluted. 
  Several 
  reagents 
  ex- 
  

   i^ensively 
  used 
  by 
  histologists 
  have 
  the 
  effect 
  of 
  hardening 
  or 
  

   oagulating 
  tissues, 
  so 
  that 
  they 
  become 
  much 
  less 
  easily 
  

   'storted 
  by 
  subsequent 
  manipulation. 
  'Oi 
  these 
  reagents 
  

   ^'e 
  is 
  one 
  which 
  acts 
  very 
  quickly 
  and 
  produces 
  hardly 
  

   "y 
  perceptible 
  change 
  in 
  the 
  Hving 
  appearance 
  of 
  the 
  tissue 
  

   ^^ 
  organism, 
  simply 
  fixing 
  and 
  preserving 
  the 
  details 
  of 
  its 
  

  

  add^^\^'- 
  ^^^^^ 
  ^^ 
  ^^^ 
  substance 
  known 
  as 
  osinic 
  or 
  perosniic 
  

  

  •';• 
  I^ 
  is 
  used 
  in 
  aqueous 
  solution 
  of 
  a 
  strength 
  not 
  exceed- 
  

  

  J, 
  one 
  per 
  cent, 
  of 
  the 
  acid. 
  Experience 
  has 
  shown 
  that 
  

  

  