238 HISTORY OF BRITISH ZOOPHYTES. 



the testacea, fall a prey to the Actinia," — " The remarkable 

 voracity of this creature warns the naturalist to beware of its 

 presence among his collections, otherwise they shall as- 

 suredly perish. Simple contact of the tentacula is the pre- 

 lude of destruction. Some animals, as if conscious of their 

 inevitable fate, seem paralysed by the touch, and yield 

 without a struggle. Others, whose size and strength 

 should ensure indemnity, are held in its relentless grasp ; 

 the tentacula crowding faster and faster around, until the 

 victim is speedily swallowed alive.'^ Sir John says, that he 

 has no proof that the Actinia is victorious in consequence of 

 discharging some deleterious fluid on its living prey, as 

 many naturalists have supposed ; and he gives it as his 

 opinion, that in many cases it is quite evident that superior 

 power is the only means employed for victory. Dr. John- 

 ston, however, holds a different opinion, founded on ob- 

 servations made by acute naturalists. "To disable the 

 animal and render its struggles for escape unavailing, the 

 class is furnished with poison-vesicles and spicula, similar 

 to those which have been described as existing in the ten- 

 tacula of the Hydra," These organs were first discovered, 

 I believe, by M. Quatrefages, but they have been described 

 also by Wagner and Erdl. They are little elliptical capsules 



