16 ZOOPHYTA. 



or cells. This is the condition of the Sertulariadce 

 and the Plumulariadce. 



Others are not enclosed in a tribe, but deposit in 

 the substance of the flesh crystal-like sjpicula of 

 lime, somewhat like those of the Sponges, which 

 serve to stiffen and support the mass, as the Alcyo- 

 nium or " Cow's-pap." The extensive group known 

 popularly as Sea-anemones, or Animal-flowers, 

 from the blossom-like appearance of their expanded 

 disks and tentacles, and their gorgeous colours, are 

 more fleshy, but are destitute of any solid parts ; 

 while the Madrepores have a skeleton composed of 

 stony plates set up edgewise, and imbedded in the 

 flesh in a radiating fashion round the centre. 

 Finally, the Gorgonice are long and slender, with 

 a flexible axis of horny or wood-like substance. 



Most, if not all, of these Polypes have the power 

 of arresting, by a touch of their bodies, other 

 animals much higher in rank than themselves, and 

 of instantly benumbing them, so that they may be 

 sucked in and devoured without resistance. This 

 power resides in highly elastic threads or wires, 

 which are doubtless connected with a subtile 

 poison, and are ordinarily coiled up in oval cap- 

 sules, but are, at the will of the animal, projected 

 with surprising force. These capsules are lodged 

 in vast numbers in the flesh of the body, but 

 especially in the tentacles.* 



Localities, &c. — The Tubidariadce and Sertula- 

 riadce are for the most part found growing on 

 rocks, stones, or shells, from half-tide level to deep 

 water. Some, as the Coryne and the Campanula- 

 riadce, are more often found on sea-weeds. The 



* See my observations on these organs in " The Devonshire 



Coast," passim. 



