218 THE MICROSCOPE. 



red to a deep orange. It grows in large hemispherical masses, from 

 one to two feet in circumference : these first appear as small specks 

 adhering to a shell or rock ; as they increase, the tubes resemble a 

 group of diverging rays, and at length the other tubes are produced on 

 the transverse plates ; thus filling up the intervals, and constituting 

 a uniform tubular mass ; the surface being covered with a green fleshy 

 substance beset with stellular animalcules. 



ACTINIAE. 



All persons accustomed to wander by the sea-shore must have ad- 

 mired the livid green, dark little jelly-masses adhering to the rocks, 

 called Actinia, from a Greek word signifying a ray, and le.ft in some 

 little pool by the ebbing tide, living as they do principally within high 

 and low-water mark, and expanding their broad surfaces and fringing 

 feelers to the finger of inquisitive youth, so often thrust into the centre 

 to feel the effect of the suction, as the poor animal draws itself up in the 

 form of a little fleshy hillock. TheActinice have the power of secreting 

 some adhesive substance at their base, by which they affix themselves to 

 rocks and other objects..; but can release their bodies when necessary, 

 and, either by creeping on their feelers, or filling their bodies with 

 water, and gliding along, change their location. Much interest has 

 been excited by the exhibition of many of this class in the tanks in the 

 Zoological Gardens. These zoophytes are more familiarly known by 

 the name of Sea-Anemonies, or Animal Flowers : they belong to the 

 order Helianthoida ; the polyps are single, free, or permanently attached; 

 fleshy, naked, or encrusted with a calcareous polypidom, the upper sur- 

 face of which is crossed by radiating lamella?. Eepresentations are 

 given of them in the Frontispiece, Nos. 5, 6, and 7, and elsewhere. 



In their appetites they are voracious, and seize the little shelled in- 

 habitants of the sandy shores. Dr. Johnston says : " I had once brought 

 me a specimen of Actinia gemmacea, that might have been originally 

 two inches in diameter, and that had somehow contrived 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 completely into 

 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 it- 

 self of what had undoubtedly been a very untoward accident, to increase 

 its enjoyments and its chances of double fare. A new mouth, furnished 



