POSSESSION. 15 
Tying several of them tightly round to prevent 
the worm escaping, I brought them home 27 sztw. 
At least four out of every six contained a para- 
site, and, what is rather strange, the worms were 
nearly all of one size. A query or twonaturally 
suggest themselves. How did this friend or 
intruder, whichever it may be, first get installed 
asalodger? Did he get in as a baby, and thus 
become an adopted child; or did he slip in as a 
full-grown annelide, defying the Keyhole Limpet 
to turn him out? How does he procure food; and 
on what does he subsist? I confess utter inability 
to give a satisfactory reply: my impression, how- 
ever, 1s, that the parasite grows from a minute 
germ (if that is a right term) in the place and 
position in which I found it. 
I put them in sea-water, after taking them out 
of their sanctuary, but in no single instance did 
one ever go back again. I tried to replace them, 
but could never accomplish it, or induce the worm 
to remain. Not that this proves anything, inas- 
much as experience teaches that interference 
with the regular habits of any of the lower forms 
of life is at once resented; and the power, or will 
it may be, to adapt itself to altered circumstances 
is but slowly acquired. I cannot conceive the 
possibility of a large worm, the feet armed with 
