156 INTELLIGENT BEHAVIOUR 
But one must make sure that they are just leaving or returning 
to their proper homes, and are not taken in the midst of a 
more extended peregrination, as in that case their special scars 
cannot be noted. Failure to be careful in this matter vitiated 
my earlier observations, which are therefore excluded in the 
following table :— 
Number returned. 
Number Distance 
removed. in inches. 
In 2 tides. In 4 tides. Later. 
25 6 21 _— _— 
21 12 13 5 al 
21 18 10 6 2 
36 24 1 1 3 
From the nature of the rock surfaces the removal of a 
limpet to a distance of two feet almost invariably involved 
placing them on the further side of an angle. And though 
some returned over such an angle, the majority did not. 
In most cases the individuals which failed to return to 
their respective scars took up new positions; and in several 
instances, when they were subsequently removed to a distance 
of a few inches from this new position, they returned to it. 
Their return to the scar was watched in many cases, and the 
course was fairly, but not quite direct. One limpet covered a 
distance of ten inches, over a somewhat curved course, in a 
little under twenty minutes. In another case the limpet on its 
return journey had to pass between two others, which necessi- 
tated the lifting of the shell to some height so as to clear one 
of them. On reaching the scar they twist and turn about so 
as to fit down in the normal position which is constant. When 
they come up the wrong way round they rotate pretty rapidly 
through the 180 degrees to get into position. One was 
observed to make a short excursion from and return to its scar 
under stillish water. But as a rule they seem to remain fixed 
when they are submerged, moving for the most part when the 
tide has just receded. 
