206 



HARDWICKE'S SCIENCE-GOSSIP. 



[Sept. 1, 1S69. 



every point, and adhere by suction with consider- 

 able tenacity, throwing out, according to Gaertuer, 

 of their whole surface a number of extremely 

 minute suckers, which, sticking fast to the small 

 protuberances of the skin, produce the sensation of 

 roughness, which is so far from being painful that 

 it even cannot be called disagreeable. 



" The size of the prey is frequently in unseemly 

 disproportion to the preyer, being often equal iu 

 bulk to itself. I had once brought me a specimen 

 of A. crassicornis, that might have been originally 

 two inches in diameter, which had somehow con- 

 trived to swallow a valve of Pecten maximus of the 

 size of an ordinary saucer. The shell, fixed within 

 the stomach, was so placed as to divide it com- 

 pletely iuto two halves, so that the body, stretched 

 tensely over, had become thin and flattened like a 

 pancake. All communication between the inferior 

 portion of the stomach and the mouth was of course 

 prevented ; yet, instead of emaciating and dying of 

 atrophy, the animal had availed itself of what 

 undoubtedly had been a very untoward accident, to 

 increase its enjoyment and its chance of double 

 fare. A new mouth, furnished with two rows of 

 numerous tentacula, was opened up on what had 

 been the base, and led to the under stomach ; the 

 individual had indeed become a sort of Siamese 

 twin, but with greater intimacy aud extent in its 

 unions ! " 



The sea anemones pass nearly all their life fixed 

 to some rock, to which they seem to have taken 

 root. There they live a sort of unconscious and 

 obtuse existence, gifted with an instinct so obscure 

 that they are not even conscious of the prey in their 

 vicinity until it is actually iu contact, when it seizes 

 it in its mouth and swallows it. Nevertheless, 

 though habitually adherent, they can move, gliding 

 and creeping slowly by successive contractile and 

 relaxing movements of the body, extending one 

 edge of their base and relaxing the opposite one. 



At the approach of cold weather the Actinia-dec 

 descend into the deepest water, where they find a 

 more agreeable temperature. 



We have said that the sea anemones are scarcely 

 possessed of vital instinct ; but they are capable of 

 certain voluntary movements. Under the influence 

 of light, they expand their tentacles as the daisy 

 displays its florets. If the animal is touched, or the 

 water is agitated in its neighbourhood, the tenta- 

 cles close immediately. These tentacles appear 

 occasionally to serve the purpose of offensive arms. 

 The hand of the man who has touched them 

 becomes red and inflamed. M. ITollard has seen 

 small mackerel, two to three inches long, perish 

 when touched by the tentacles of the Green Actinia 

 (Comactis viridis, Allman). This is a charming 

 little animal ; " the brilliancy of its colours and the 

 great elegance of its tentacula crown when fully 

 expanded," says Professor Allman, "render it 



eminently attractive ; hundreds may often be seen 

 in a single pool, and few sights will be retained with 

 greater pleasure by the naturalist than that pre- 

 sented by these little zoophytes, as they expand 

 their green and rosy crowns amid the algae, 

 millepores, and plumy corals, co-tenants of their 

 rock-covered vase." 



The toxological properties of the Actinia have 

 been attributed to certain special cells full of liquid; 

 but M. Hollard believes that these effects are 

 neither constant enough nor sufficiently general to 

 constitute the chief function of these organs, which 

 are found in all the species aud over their whole 

 surface, external and internal. Though quite in- 

 capable of discerning their prey at a distance, the 

 sea anemone seizes it with avidity when it comes to 

 offer itself up a victim. If some adventurous little 

 worm, or some young and sluggish crustacean, hap- 

 pens to ruffle the expanded involucrum of an actinia 

 in its lazy progress through the water, the animal 

 strikes it at once with its tentacles, and instinctively 

 sweeps it into its open mouth. This habit may be 

 observed in any aquarium, and is a favourite spec- 

 tacle at the " Jardin d'Acclimitation " of Paris at 

 noon on Sunday and Wednesday, when the aquatic 

 animals are fed. Small morsels of food are thrown 

 into the water. Prawns, shrimps, and other crusta- 

 ceans and zoophytes inhabiting this medium chase 

 the morsels as they sink to the bottom of the basin; 

 but it is otherwise with the Actinia ; the morsels 

 glide downwards within the twentieth part of an 

 inch of their crown without its presence being sus- 

 pected. It requires the aid of a propitious wand, 

 directed by the hand of the keeper, to guide the 

 food right down on the animal. Then its arms or 

 tentacles seize upon the prey, and its repast com- 

 mences forthwith. 



The Actinia are at once gluttonous and voracious. 

 They seize their food with the help of the tentacula, 

 and engulf in their stomach, as we have seen, sub- 

 stances of a volume and consistence which contrast 

 strangely with their dimensions and softness. Iu 

 less than an hour M. Hollard observed that one of 

 these creatures voided the shell of a mussel, and 

 disposed of a crab all to its hardest parts ; nor was 

 it slow to reject these hard parts, by turning its 

 stomach inside out, as one might turn out one's 

 pocket, in order to empty it of its contents. We 

 have seen in Dr. Johnston's account of A. crassi- 

 cornis that when threatened with death by hunger, 

 from having swallowed a shell which separated it 

 into two halves, at the end of eleven days it had 

 opened a new mouth, provided with separate rows 

 of tentacula. The accident which, in ordinary 

 animals, would have left it to perish of hunger, be- 

 came in the sea anemone the source of redoubled 

 gastronomical enjoyment. 



" The anemones," Fredol tells us, " are voracious 

 and full of energy ; nothing escapes their gluttony ; 



