230 HISTORY OF BRITISH ZOOPHYTES. 
Actinia, and that its formation presents a striking instance 
of the operation of that beautiful law of Nature which 
makes the habits of one animal subservieut to the wants of 
another.” I may insert the following, which Dr. Johnston 
is pleased to quote at this place from my ‘ Excursions to the 
Island of Arran :’—‘ Many naturalists have observed that 
there seems to be a treaty of union betwixt the hermit-crab 
and the spotted sea-anemone. I lately kept one of these 
pretty creatures for some days in sea-water; it had fastened 
itself to a little fragment of a screw-shell (Zurritella terebra), 
but its co-tenant in the inside was not a hermit-crab, but a 
pretty red annelide. Be this as it may, certain it is that 
on this occasion we found that the spotted anemone had 
fastened itself to the outer lip of many of the roaring 
buckies (Buccinum undatum) brought up by the dredge, and 
whenever there was an anemone without, there we found 
a hermit-crab within. In all likelihood they in various 
ways aid each other. The hermit has strong claws, and 
while he is feasting on the prey he has caught, many spare 
crumbs may fall to the share of his gentle-looking com- 
panion. But soft and gentle-looking though the Actinza 
be, she has a hundred hands, and woe to the wandering 
wight who comes within the reach of one of them, for all 
