POL 



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POL 



duction, and show no generative 

 organs. The greater part of the 

 species adhere one to another, and 

 may be considered as animals de- 

 pending on mutual support. Some 

 of them approach closely to the 

 Infusoria, as the Polypi Ciliati, 

 whilst others are capable of attach- 

 ing themselves by means of a pedi- 

 cle, and in many instances are able 

 to detach and affix themselves to 

 new spots. 



These animals are commonly 

 known as Corals. From an idea 

 which long prevailed that these 

 animals are allied to marine plants, 

 they also obtained the name of 

 Zoophytes. The body is cylindri- 

 cal or conical, sometimes possessing 

 no viscus but its cavity ; at others 

 possessing a stomach, which is vi- 

 sible, and other organs. The 

 greater number of Polyparia are 

 inhabitants of the ocean, and from 

 the ocean's depths they raise those 

 immense reefs that at some future 

 period may form a communication 

 between the inhabitants of the 

 temperate zones. Although Polypi 

 abound in every part of the ocean, 

 still it is in the warmer regions 

 that they grow in greatest luxuri- 

 ance. The tentacula of Polypi are 

 exquisitely sensitive, and are fre- 

 quently seen, either singly or alto- 

 gether, bending their extremities 

 towards the mouth when any mi- 

 nute floating body comes in contact 

 with them. A question arises, 

 says Dr. Eoget, with regard to the 

 constitution of these Zoophytes, 

 similar to that which has been 

 proposed with regard to trees, 

 namely, what limit should be as- 

 signed to their individuality ? Is 

 the whole mass, which appears to 

 grow from one root, and which 

 consists of multitudes of branches, 

 proceeding from a common stem, 

 to be considered as one individual 

 animal, or is it an assemblage, or 

 aggregation of smaller individuals ; 



each individual being characterised 

 by having a single mouth, with its 

 accompanying tentacula, and yet 

 the whole being animated by a com- 

 mon principle of life and growth ? 

 The greater number of naturalists 

 have adopted this latter view, re- 

 garding each portion as provided 

 with a distinct circle of tentacula, 

 as a separate animal, associated 

 with its neighbours in the con- 

 struction of a common habitation, 

 and contributing its quota to the 

 general nourishment of this animal 

 republic. 



POLYPHRA'CTUS. A genus of ichthyo- 

 lites of the old red sandstone. 



POLYPI'FERA. j That class of animals 



POLYPI'PHERA. j commonly known 

 by the name of Zoophytes. They 

 are carnivorous, feeding upon living 

 animalcules. These animals preci- 

 pitate immense quantities of carbo- 

 nate of lime, especially in tropical 

 seas. 



" These," says Prof. Grant, " are 

 soft aquatic animals of a plant-like 

 form, generally fixed, and supported 

 by an extra- vascular axis of a cal- 

 careous or horny texture. Instead 

 of the pores of the poriphora, the 

 common fleshy mass of the body 

 here developes small tubular di- 

 gestive sacs called polypi, the 

 margins of which are furnished 

 with sensitive tentacula, and the 

 sides of the tentacula are almost 

 always furnished with sensitive, or 

 prehensile, or vibratile cilia." 



POLYPI'FEROTJS. Animals which have 

 polypi ; zoophytes. 



POLYPE'TALOUS. (from TTO\VS, many, 

 and Tre-raXov, a leaf of the corolla, 

 Gr.) In botany, a term applied to 

 a corolla which has the petals sepa- 

 rate. 



POLYSE'PALOFS. (from 7ro\i><?, many, 

 and sepal, the name given to the 

 parts of which the calyx is compo- 

 sed.) In botany, a term given to 

 a calyx which has its sepals sepa- 

 rate from each other. 



