POSSESSION. 15 



Tying several of them tightly round to prevent 

 the worm escaping, I brought them home in situ. 

 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 two naturally 

 suggest themselves. How did this friend or 

 intruder, whichever it may be, first get installed 

 as a lodger? Did he get in as a baby, and thus 

 become an adopted child ; or did he slip in as a 

 full-grown aiinelide, 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, is, 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 



