variety  is  capable  of  surviving  for  a  sniiilar  period.  Assuming  this 
to  be  the  case,  and  we  add  to  these  data,  the  period  from  the  time 
the  female  drops  from  the  host  to  the  hatching  of  the  larvae  or  ‘  grass 
lice,’  we  find  that  the  non-parasitic  period  may  range  from  93 
to  200  days,  approximately,  so  that  these  data  give  us  important 
information  on  the  question  of  tick  eradication,  in  so  far,  at  least,  as 
the  Texas  fever  tick  is  concerned.  But  we  have  little  to  guide  us 
m  regard  to  the  other  Jamaican  species  (A.  cajanense),  though  we 
have  ascertained  the  facts  regarding  the  incubation  period  of  the  eggs 
and  other  matters  relating  to  the  earlier  stages  of  this  pest. 
Many  interesting  details  could  be  given  here  in  relation  to  the 
longevity  of  various  kinds  of  ticks  found  in  other  parts  of  the  world, 
but  such  facts  could  have  no  practical  bearing  on  the  subjects  under 
consideration. 
One  authority  claims  that  ‘  young  ticks  or  “  grass  lice  ”  stick  the 
juice  from  the  young  blades  of  grass  and  grow  and  thrive  upon  it 
until  a  better  host  comes  along  ’ ;  further  that  the  ‘  young  and  tender 
shoots  of  the  springing  that  follows  burning  affords  an  irresistible 
temptation  to  young  ticks  ....  so  much  so  that  they  can  be  seen  in 
millions  going  from  adjoining  pastures  to  a  newly  burnt  one.’  It  is  a 
commonly  accepted  theory  among  peasantry  also  that  ticks  can  live 
and  multiply  without  an  animal  host,  becoming  blood  suckers  when 
occasion  serves,  and  though  it  may  appear,  in  some  cases,  as  if  this 
were  founded  on  fact,  the  inference  is  wrong.  There  is  no  evidence 
that  ticks  of  any  kind,  can  survive  or  mature  on  a  vegetable  diet. 
LIFE  CYCLE  OF  TICKS 
Some  details  concerning  the  life  histones  of  the  Jamaican  ticks 
are  given  in  this  Report  (pp.  434-446),  which,  so  far  as  they  go, 
form  a  basis  for  economic  procedure  in  dealing  with  tick-infested 
pastures. 
All  ticks  undergo  a  metamorphosis  which  consists  of  the  following 
stages:  I,  the  egg;  2,  the  larva  or  'grass  louse’  stage;  3,  the 
nymph  ;  and  4,  the  sexually  mature  stage. 
^ggs-  These  are  laid  upon  the  ground  in  masses,  apparently 
m  sheltered  spots.  At  first  they  are  pale  brownish-yellow, 
but  eventually  change  to  translucent  brown,  resembling  the  colour 
