286 JELLY-FISH, STAR-FISH, AND SEA-URCHINS. 
experimentally by drawing a piece of sea-weed over 
the surface ofa healthy Echinus in the water. The 
moment the sea-weed touches the surface of the 
animal, it is seen and felt to be seized by a number. 
of these little grasping organs, and—unless torn 
away by a greater force than is likely to occur in 
currents below the surface of the sea—it is held 
steady till the ambulacral suckers have time to 
establish their attachments upon it. Thus there is 
no doubt that the pedicellariz are able efiiciently 
to perform the function which we regard as 
their chief function. We so regard this function, 
not merely because it is the one that we observe 
these organs chiefly to perform, but also because 
we find that their whole physiology is adapted 
to its performance. Thus their multitudinous 
number and ubiquitous situation all over the 
external surface of the animal is suggestive of 
their being adapted to catch something which may 
come upon them from any side, and which may 
have strings and edges so fine as to admit of being 
enclosed by the forceps. Again, the instantaneous 
activity with which they all close round and seize 
a moving body of a size that admits of their seizing 
it, is suggestive of the objects which they are 
adapted to seize being objects which rapidly brush 
over the surface of the sheli, and therefore objects 
which, if they are to be seized at all, must be seized 
instantaneously. Lastly, we find, on experiment- 
ing upon pedicellariz, whether wn situ or when 
separated from the Echinus, that the clasping action 
of the forceps is precisely adapted to the function 
