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the polype were sadly in need of protection , but that is not 

 the case ; it possesses excellent weapons of defence. In many 

 parts of the body, but chiefly on the tentacles which serve to 

 catch the prey, there are numerous microscopic blisters , the 

 so-called nettle-cells, each of which contains an acrid fluid and 

 spirally rolled up filaments. When the animal comes in con- 

 tact with an enemy or its prey , it darts out some hundreds 

 of such nettle-filaments, and the fluid which issues from them 

 at the same moment has a benumbing and even deadly effect 

 on many of the smaller organisms. The Actiniae, most highly 

 organised of polypes, are uncommonly greedy, and devour not 

 only the bits of meat given it, but catch all the living worms , 

 crabs, snails and fishes that come within their reach. An acti- 

 nia, a Sagartia parasitica, caught and devoured an octopus 

 much larger than itself. A large Anthea caught and con- 

 sumed a shark above a foot long. The extraordinary tenacity of 

 life in the Actiniae very much facilitates their preservation in 

 the tanks ; in many cases we have kept the same individual 

 alive for years. One lived, it is said, for more than forty years 

 in a small aquarium at Edinburgh , and during that period 

 brought forth above a thousand young ones. 



Among the numerous beautifully coloured kinds we notice 

 the Anthea cereus, so often found in the Gulf of Naples , 

 examples of which are seen clustered together on a rock like 

 flowers on a bed. 



Still more splendid than this Anemone , which has hitherto 

 been found only in the Gulf of Naples, is the remarkable Cla- 

 dactis Costae. This animal lives at a considerable depth. At 

 first we could not succeed in keeping it alive in the Aqua- 

 rium , but since the last few years the examples taken live 

 for many months. In its expanded state the Cladactis is cer- 

 tainly one of the most beautiful of sea-anemones. The Sagar- 

 tia is interesting from its habits; it lives on the shell of the 

 Hermit-crab, and allows its host to carry it about. The Acti- 

 nia Mesembryanthemum is often eaten in Naples, and the 

 Anthea also. 



After examining the Actiniae it is easier to understand the 

 structure of the true corals. If the Actiniae were capable of se- 

 creting an outer or inner calcareous skeleton , that skeleton, 

 after death, would be valued, like a coral , as an ornamental 

 substance. The beautiful orange-coloured Astroides, which co- 

 vers the rocks of the Aquarium, is such an Actinia with a ske- 

 leton. Its true form can only be seen when the sky is over- 



