IN THE SHETLANDS 45 
fication might, in course of time, be expected, the 
present truth should be most carefully made out, and 
having been accurately recorded and published, obser- 
vation, after a certain length of time, should again be 
focussed on the same points, and this being renewed 
every ten, twenty, fifty, or a hundred years, the results 
could be compared. For instance, our green wood- 
pecker feeds now largely upon ants in their nests, 
whilst it both fights and copulates upon the ground. 
How interesting would it be if we had a continuous 
record of observations of this bird’s habits, dating, 
say, from William the Conqueror or the days of the 
Saxon Heptarchy, and if we found that no mention 
was made of these peculiarities, by the field naturalists 
of those times, but that they first began to be doubt- 
fully recorded in the reign of Henry the Fifth, or 
Richard the Third. No doubt a connected chain of 
evidence of this kind will gradually grow up, owing 
to the accumulation of works of natural history, but 
it would, I think, be a great deal more satisfactory if 
the object were kept steadily in view, and I am quite 
sure that observations made in this spirit would pro- 
duce much more interesting matter than that which 
is to be found in the ordinary bird or beast book. 
For the great idea would then be to compare the 
present with the past habits of any creature, in order 
to see whether, or in what degree, they have changed, 
and this could only be done by continual re-observa- 
tion, which would assuredly lead to novelty of some 
sort, instead of mere repetition, which is what we 
