NO.    I  ARCHEOLOCV    OF    ST.    LAWRENCE    ISLAND COLLIN.S  97 
period,  the  nature  of  the  transition  would  be  clearer,  but  the  fact  that 
there  are  so  few  specimens  on  which  the  two  art  styles  are  combined 
is  in  itself  evidence  that  it  was  a  period  of  no  long  duration.  There 
is,  of  course,  no  reason  to  believe  that  Punuk  art  had  its  origin  at  this 
particular  site.  We  know  that  it  was  by  no  means  limited  to  St. 
Lawrence  Island,  even  though  it  seems  to  have  been  more  prominent 
there  than  elsewhere.  The  existence  of  even  a  few  specimens  such 
as  those  just  described  suggests  the  possibility  that  future  excavations 
may  reveal  a  more  gradual  transition  between  the  two  styles.  In  this 
connection  there  will  be  other  evidence  to  consider,  especially  harpoon 
heads ;  as  we  shall  see  presently,  these  were  undergoing  constant  modi- 
fication during  the  Old  Bering  Sea  and  Punuk  periods,  and  there  is 
ample  evidence  that  in  this  case  the  transition  from  one  stage  to  the 
other  was  quite  gradual. 
HARPOON    HEADS,    OLD    BERING    SEA 
Of  the  many  ingenious  devices  which  have  enabled  the  Eskimo  tu 
meet  the  needs  of  their  exacting  environment,  none  is  of  more  im- 
portance than  the  harpoon.  Without  such  an  effective  means  of  cap- 
turing the  sea  mammals  on  which  they  so  largely  depend,  the  Eskimo 
could  hardly  have  adapted  themselves  to  a  life  on  the  Arctic  coasts. 
Fortunately  for  our  present  purpose,  the  harpoon  is  a  complex  im- 
plement, which  differs  from  one  locality  to  another ;  furthermore, 
archeological  investigations  have  shown  that  throughout  the  course 
of  its  history  it  has  been  undergoing  constant  modification.  Regional 
variations  and  developmental  changes  may  be  observed  in  various 
parts  of  the  harpoon — in  the  ice  pick  at  the  butt  end,  the  bone  or  ivory 
finger  rest,  the  socket  piece,  the  foreshaft,  but  most  particularly  in 
tlie  detachable  bone  or  ivory  head.  The  toggle  harpoon  head  is  the 
most  dependable  criterion  of  cultural  change  at  our  disposal,  and  as 
such  it  is  destined  to  bear  the  main  weight  of  the  chronology  that 
must  be  established  if  we  are  to  have  a  clear  understanding  of  the 
stages  of  development  in  Eskimo  culture.  As  a  "  time  indicator  ",  the 
harpoon  head  occupies  a  position  in  Eskimo  culture  analogous  to  that 
of  pottery  in  the  Southwest.  To  a  peculiar  degree  it  possesses  the 
characteristics  which  Kidder  has  described  as  essential  to  any  class 
of  material  that  is  to  be  utilized  for  diagnostic  purposes. 
Valid  cultural  histories  ....  can  only  be  compiled  by  studying  series  of  speci- 
mens whose  age,  relative  to  each  other,  is  known.  Only  from  chronologically 
seriable  specimens  can  dependable  conclusions  be  drawn  as  to  the  origin  and 
spread  of  culture  traits  and  as  to  the  improvement  or  decline  of  techniques 
But  the  time  sequence  of  archeological  materials  is  usually  very  hard  to  establish. 
