SCIENTIFIC NEWS. 15^ 



the cavities of which are divided by lamelloe disposed in a 

 stellular form. The animal, which in the recent coral fills 

 these cavities, was first depicted by Donati in the 47th vo- 

 lume of the Philosophical Transactions, p. 105, PI. IV, 

 and in the Natural History of the Adriatic Sea by the same 

 author. Its feet are in considerable number, and terminate 

 externally in two conical prod actions, which, being placed 

 on each side of every one of the lamellae that give the stel- 

 lular form to the cavity of the coral, serve to affix the ani- 

 mal to the circumference of its cell, and may with propriety 

 be considered as the instruments, by which the little animal 

 forms the lamellae themselves. The bases of these conical 

 productions unite and form round bodies, which possess 

 somewhat of the figure and of the properties of a muscle : 

 they undoubtedly serving to lengthen or shorten the feet, 

 and also most probably to regulate the force, with which 

 they clasp the lamellae, on which they exert their plastic 

 powers. The other ends of these round bodies terminate in 

 small cylindrie tubes, which are attached to the shell of the 

 animal, in the centre of which is seen its head, capable of 

 moving with great quickness, and ornamented with several 

 rays, which are most probably the arms or claws with which 

 it seizes and secures the animalculae on which it feeds. 



Attributing the formation of these corals to the operations Manner in 

 of the madreporean or medusean polype, let us endeavour to which the co- 

 trace the little architect through its wonderful labours. ral is formed * 

 Agreeable to the observations of Donati, each of the legs, 

 as he terms them, of the polype are provided with two pro- 

 cesses, which are applied to each side of one of the perpen- 

 dicular laminae, whilst a muscular pyriform body, attached 

 to the other end of the leg, gives to it the power of employ- 

 ing that motion which is necessary for the accomplishment 

 of its task. The young polype, disposed on an appropriate 

 spot, may be considered as completing its operations by two 

 distinct processes: the secretion and separation of carbonate 

 of lime from the sea water, conveyed through the pyriform 

 body ; and its deposition, at its moment of secretion, by 

 the two small processes, where the economy of the animal 

 directs. Proportioned to the number of legs possessed by 

 the infant animal was probably the number of perpendicu- 

 lar 



