﻿41 
  LAURENCE 
  D. 
  CLEARE, 
  JNR. 
  

  

  varied 
  from 
  3 
  feet, 
  the 
  width 
  of 
  the 
  netting, 
  down 
  to 
  a 
  few 
  inches. 
  If 
  it 
  is 
  desirable 
  

   to 
  use 
  cages 
  taller 
  than 
  3 
  feet, 
  and 
  this 
  will 
  only 
  be 
  very 
  rarely, 
  the 
  height 
  may 
  be 
  

   increased 
  by 
  joining 
  on 
  an 
  additional 
  strip 
  of 
  netting 
  by 
  means 
  of 
  paper-fasteners. 
  

  

  Originally, 
  fine 
  muslin, 
  held 
  in 
  place 
  by 
  rubber 
  bands, 
  was 
  used 
  for 
  the 
  tops 
  of 
  these 
  

   cages 
  ; 
  but 
  after 
  some 
  large 
  larvae 
  were 
  attacked 
  by 
  rats 
  the 
  dishes 
  came 
  into 
  use. 
  

   Obviously 
  muslin 
  can 
  still 
  be 
  used 
  in 
  certain 
  places 
  with 
  advantage, 
  especially 
  when 
  

   weight 
  has 
  to 
  be 
  considered. 
  

  

  The 
  wire 
  netting 
  is 
  usually 
  fitted 
  inside 
  the 
  dishes 
  both 
  top 
  and 
  bottom, 
  but 
  in 
  

   cases 
  where 
  earth 
  is 
  necessary 
  for 
  pupation 
  it 
  is 
  advantageous 
  to 
  fit 
  the 
  cylinder 
  

   outside 
  the 
  bottom 
  ; 
  the 
  advantage 
  of 
  this 
  will 
  be 
  found 
  when 
  lifting 
  off 
  the 
  wire 
  to 
  

   replace 
  the 
  food-plant. 
  Food-plants, 
  of 
  course, 
  have 
  their 
  stems 
  placed 
  in 
  small 
  

   bottles 
  or 
  other 
  receptacles 
  containing 
  water. 
  

  

  Cages 
  of 
  this 
  type 
  have 
  been 
  used 
  in 
  tick 
  breeding 
  experiments 
  by 
  Mr. 
  G. 
  E. 
  Bodkin, 
  

   and 
  when 
  thus 
  employed 
  were 
  placed 
  in 
  larger 
  dishes 
  containing 
  water 
  and 
  kerosene 
  

   oil 
  to 
  prevent 
  the 
  escape 
  of 
  the 
  ticks. 
  This 
  method 
  could 
  also 
  be 
  used 
  to 
  prevent 
  

   attacks 
  of 
  ants, 
  which, 
  in 
  this 
  Colony 
  at 
  least, 
  have 
  always 
  to 
  be 
  considered 
  in 
  insect 
  

   breeding. 
  

  

  It 
  may 
  here 
  be 
  mentioned 
  that 
  in 
  this 
  laboratory 
  all 
  tables 
  used 
  for 
  breeding 
  ex- 
  

   periments 
  are 
  kept 
  standing 
  in 
  bowls 
  containing 
  water 
  and 
  kerosene 
  oil. 
  Were 
  the 
  

   bare 
  wooden 
  legs 
  of 
  a 
  table 
  placed 
  in 
  this 
  mixture 
  the 
  oil 
  would 
  penetrate 
  the 
  wood 
  

   and 
  ruin 
  the 
  legs. 
  Professor 
  Harrison 
  has 
  devised 
  a 
  method 
  to 
  avoid 
  this 
  ; 
  small 
  

   iron 
  rods 
  about 
  6 
  inches 
  long 
  and 
  1 
  inch 
  in 
  diameter 
  are 
  driven 
  perpendicularly 
  into 
  

   the 
  legs 
  and 
  it 
  is 
  these 
  that 
  come 
  in 
  contact 
  with 
  the 
  mixture 
  of 
  oil 
  and 
  water.* 
  

  

  * 
  [As 
  an 
  alternative 
  to 
  water 
  and 
  kerosene, 
  dusting 
  me 
  saucers 
  occasionally 
  with 
  

   pyrethrum 
  powder 
  has 
  been 
  found 
  very 
  effective 
  in 
  keeping 
  off 
  ants 
  ; 
  this 
  has 
  the 
  

   advantage 
  that 
  the 
  legs 
  of 
  the 
  table 
  require 
  no 
  special 
  adaptation. 
  — 
  Ed.] 
  

  

  