Of Cliiftering Polypes . 337 
Water, or touching them with any foreign 
Body, both Stem and Branches inftantly con¬ 
tract together, and extend not again till 
every thing is perfectly at reft. 
But though they are found thus conjoined 
in Colonies, each Head is a perfedt Animal, 
and can detach itfelf from the reft, live fe- 
parately, .and become the Parent of a new 
Colony, as moft of them do after a certain 
Time. All of the fame Community adt af¬ 
ter one common Law, in contradting or ex¬ 
tending the main Stem as well as their re- 
fpedtive Pedicles at the fame Time, though 
each can contradt or ftretch itfelf out at 
Pleafure, without the Concurrence of the 
reft, as far as the Extent of its own Pedicle. 
When a whole Colony contracts together, 
the main Stem feems to pull back the feve- 
ral Pedicles, and thofe Pedicles the little 
Animals at their Extremities : but here the 
Truth is contrary to the Appearance, for the 
Animals themfelves begin the Motion that 
pulls them back, by a fudden Endeavour to 
draw up their Pedicles to their Bodies, which 
Motion the Pedicles communicate to the 
main Stem, and thereby contradt that alfo; 
fomewhat in the Manner of a Hair, which 
jerked fuddenly (not to break) and then let 
go again, hies back with an elaftic Force. 
And that the Cafe is thus feems pretty cer¬ 
tain, becaufe after one of thefe Animals 
breaks off from its Pedicle, and leaves the 
. Vol. II. % Colony, 
