DAHLIA WARTLET. 81 



ordinary capsules, called cnidce, or nettling- cells, found 

 indeed in most of the tissues, but nowhere in such 

 abundance as here, which eject with amazing force a 

 poisonous filament having the strength and elasticity 

 of a wire, and furnished with reversed barbs, but of 

 almost inconceivable tenuity. The filaments, projected 

 by myriads at the pleasure of the animal, penetrate 

 deeply into the flesh of other soft-bodied creatures, and 

 cause immediate paralysis and speedy death. 1 



The waning day and the turning tide warn us home- 

 ward ; but we shall have time to visit a fine dark 

 overarched pool in the rocks which I know on our 

 route. Here it is ; noticeable because of its being the 

 chosen residence of a colony of that magnificent species, 

 the Dahlia Wartlet. 2 All round the curving sides of 

 the sea-washed basin, crowding one upon the other 

 beneath the projecting angles, or seated in single majesty 

 on some prominence, we see them flaunting the most 

 gorgeous colours, and attaining a diameter of expanse 

 that no other, at least of our common forms, can rival 

 or approach. The wide but low column, rough with 



1 For a fuller account of these organs and their offensive function, which 

 constitute an apparatus not exceeded in interest by any that I know of in 

 the whole realm of natural history, I beg to refer the reader to my 

 Naturalist's Rambles on the Devonshire Coast, and my A ctinolcgia Bri.tan- 

 nica, passim. 



2 Tealia crassicornis, which forms the subject of Plate VTTT. 



F 



