POLYPES. 



67 



able duration, jour sea- weeds must be procured with their 

 root-bases uninjured, the fragments of rock on which they 

 grow being knocked off by the help of a hammer and 

 chisel; but for a shorter period — a week or two, for 

 example — it will suffice to pluck up the living sea-weed 

 with the fingers, securing as much of the base as possible. 

 The bright-green weeds are the best, 



In a wash-basin of moderate size, a dozen Sea-Anemones 

 may be accommodated comfortably, and will nourish and 

 display their beauties and their instincts for an indefinite 

 period, without any further care, if the vessel be so placed 

 that the sun's light may every day fall on it, yet not so 

 exposed as to become tepid. The water, maintaining its 

 purity and its clearness, will not need to be changed ; and 

 a scene of charming interest will be constantly presented. 



The animals will soon begin to re-attach themselves by 

 their broad basal disks to the pieces of rock, or to the 

 sides of the vessel, and after a few hours will have made 

 themselves at home in their new habitation. Some of 

 them will be contented to abide week after week where 

 they first chanced to settle ; others, more restless, will 

 manifest a travelling propensity, shifting their position 

 from one part of the stone to another, or from rock to 

 rock, or crawling slowly along the sides of their prison. 

 It is true the motion is not appreciable to the eye, 

 being about as tardy as that of the hour-hand of a watch ; 

 still it is not uncommon for an Actinia to accomplish a 

 march of three or four inches in the course of a night. It 

 is effected by a gliding of the muscular base along the 

 surface, much like the crawling of a snail. 



A Sea-Anemone, or Actinia, is essentially a Hydra 5 



