58 SOMETHINO ABOUT POLYPKS, 



of similar dimensions, from a large pond in Firle Park, 1851. Some of the 

 varieties are not uncommon in the Ouse and Cuckmere Rivers, also in the 

 Pells. 



Unio pictorum, Lam. — In the Cut common, and in the Ouse occasionally, 

 varying very considerably in appearance, specimens in the Ouse being much 

 darker, and having an extraneous coat, evidently from some matter with which 

 the water is impregnated. 



I shall be happy to assist any lady or gentleman with duplicate species 

 by way of exchange. 



St. Ann's Lewes, December lAtli., 1852. 



SOMETHING ABOUT POLYPES. 



BY MRS. ARTHUR ADAMS. 



Chapter I. 



It is long since the wondrous re-productive power of the little Fresh-water 

 Polype, {Hydra viridis,) amazed the scientific world, when Trembley immor- 

 talized his name by making known its extraordinary properties. Though the 

 novelty of this discovery has subsided, and "the many" have ceased to 

 experimentalize on this poor worm, there may be some who have still to 

 learn its history, and that of the class of animals to which it belongs. 



Polypes are aquatic plant-like animals, with their mouths encircled by radiat- 

 ing tentacles somewhat like the rays of a flower; they inhabit both the ocean 

 and fresh water, and, when their numbers are considered, and what is effected 

 by their agency, we must be convinced of their importance in the economy 

 of nature. Earlier observers believed the stony Polypes to be calcareous plants, 

 and until the year 1727 they continued to be classed with the vegetable 

 kingdom, when Pleysonnel asserted their animality in an essay read before 

 the Academy of Sciences in Paris, which was received by the members of 

 that learned body with doubts and coldness. In 1711, Trembley made known 

 his remarkable experiments on the Fresh- water Polype, and this undeniable 

 proof of their animal nature caused Jussieu to surrender them to the zoologists. 

 Donati shortly afterwards followed up the research, and in speaking of the 

 animal nature of the Coral Polypes, says, "I am now of opinion that coral 

 is nothing else than a real animal, which has a very great number of heads. 

 I consider the Polypes of coral as the heads of the animal. This animal 

 has a bone ramified in the shape of a shrub; this bone is covered with a 

 kind of flesh, which is the flesh of the animal." Thus, by slow and sure 

 degrees, the true nature of the Polype began to be appreciated by the learned, 

 and has from time to time been ably commented on. Ellis, in 1754-5, 

 explained his observations and experiments to the members of the Royal Society; 

 and his work on the '^Corallines of Great Britain," exhibits such accuracy and 

 complete investigation as to be even now a standard work on this subject. 



