SEA-ANEMONES I THETB WEAPONS. 863 



or to an actual epiderm,* which, though often ruptured, 

 has ever, with the aptitude to heal common to these lowly 

 structures, the power of quickly uniting again. 



It appeared to me manifest, from this and other similar 

 observations, that no such arrangement exists as that 

 which I had fancied that a definite cinclis is assigned 

 to a definite acontium, or pair of acontia; and that the 

 extremity of the latter is guided to the former, with un- 

 erring accuracy, by some internal mechanism, whenever 

 the exercise of the defensive faculty is desired. What I 

 judge to be the true state of the case is as follows : The 

 acontia, fastened by one end to the septa, or the mem- 

 branes which support them, lie, while at rest, irregularly 

 coiled up along the narrow interseptal hollows. The 

 outer walls of these hollows are pierced with the cinclides. 

 When the animal is irritated, it immediately contracts : 

 the water contained in the visceral cavity finds vent at 

 these natural orifices, and the forcible currents carry with 

 them the acontia, each through that cinclis which happens 

 to lie nearest to it. The frequency with which a loop is 

 forced out shows that the issue is the result of a merely 

 mechanical action ; which is, however, not the less worthy 

 of admiration because of the simplicity of the contrivance ; 

 nor the less manifestly the result of Divine wisdom work- 

 ing to a given end by perfectly adequate means. The 

 ejected acontia, loaded with their deadly cnida in every 

 part of their length, carry abroad their fatal powers not 

 the less surely than if each had been provided with a 

 proper tube leading from its free extremity to the nearest 

 cinclis. 



Curious as these contrivances are, there is yet much 

 more to be told : these are preparatory and ancillary, as 

 it were, to the elaborate mechanism by which the ultimate 

 object of the whole provision is to be attained. The 



* The outer covering of the external surface of the body, commonly 

 called the cuticle or scarf-skin. 



