PAP 



[ 



PAR 



Having the surface covered with pimples 

 or dots. 



PAPI'LLOSE. In botany, a term applied to 

 stems covered with soft tubercles ; also 

 to leaves covered with fleshy dots or 

 points. 



PA'PULOUS. (from papula, Lat. a kind of 

 pimple.) Full of pimples ; pimply ; 

 blistered. 



PA'PPUS. (pappus, Lat. thistle-down. 

 TraTrTroe, Gr.) The feathery appendage 

 that crowns many seeds which have no 

 pericarpium ; a particular form of calyx 

 of which we have a familiar example in 

 the dandelion. 



PARA'BOLA. (parabola, Lat. TrapafioXfj, 

 Gr. parabole, Fr. parabola, It.) One of 

 the five conic sections : thus, if a cone be 

 cut by a plane parallel to one of its 

 sloping sides, the section will be a para- 

 bola. 



PARABO'LICK. (parabolique, Fr. parabolico, 

 It.) Having the nature or form of a 

 parabola. 



PARALLE'LOGRAM. (from TrapaXX^Xoc and 

 ypa/jjua, Gr. parallelograme, Fr. paral- 

 lelogrammo, It.) In geometry, a right- 

 lined quadrilateral figure, whose opposite 

 sides are parallel and equal. 



PARALLELOPI'PED. (parallelipipede, Fr. 

 terme de geometric. Corps solide termine 

 par six parallelogrammes dont les opposes 

 sont paralleles entre eux.*) A solid figure 

 contained under six parallelograms, the 

 opposites of which are parallel and equal ; 

 or it is a prism whose base is a parallelo- 

 gram : it is always triple to a pyramid of 

 the same base and height. 



PARA'NTHINE. A rare mineral, thus named 

 by Hauy, more commonly known as Sea- 

 polite, which see. 



PARASI'TA. (parasita, Lat. 7rapa<rtroc ? 

 Gr.) In Cuvier's arrangement, the third 

 order of Insecta ; they have six legs and 

 are apterous. Mr. Kirby observes, " the 

 order of parasites, consisting of the most 

 unclean and disgusting animals of the 

 whole class, infest both man, beast, and 

 bird, no less than four species being 

 attached to man, may be divided into two 

 sections, namely, those that live by suc- 

 tion, and those that masticate their food. 

 To the first of these belong the human 

 and the dog-louse, and to the other the 

 various lice that inhabit the birds, of which 

 almost every species has a peculiar one. 



PARASI'TIC. )1. In botany, applied to 



PARASI'TICAL. $ plants which fix their 

 roots into other plants, and from them, 

 instead of from the earth, derive their 

 nourishment : the mistletoe is a familiar 

 example. 



2. In zoology, a name given to certain 

 insects which live upon the animals they 

 infest. 



PARENCHY'MA. (rrapt-yx^fjia, Gr. paren- 

 chyme, Fr.) 



1 . A spongy or porous substance forming 

 the bulk of some of the viscera, as the 

 parenchyma of the liver, &c. 



2. In botany, a fine, transparent, mem- 

 branous tissue, lying immediately beneath 

 the epidermis of plants ; it is of a deep 

 green colour, very tender, and succulent. 

 When viewed with a microscope, it seems 

 to be composed of fibres which cross each 

 other in every direction. In its simplest 

 state, it appears like a mass of globules or 

 vesicles, crowded together ; these, from 

 pressure, assume a six-sided, or hexagonal 

 figure. 



PARENCHY'MATOUS. Consisting of paren- 

 chyma ; spongy ; porous. 



PA'RGASITE. The name given to a variety 

 of actinolite, from its being found in the 

 Isle of Pargas, in Finland. 



PARIE'TAL. (from paries, a wall, Lat.) 



1 . The name given to certain bones of the 

 skull, from their serving as walls to the brain. 



2. In botany, a term used to express an 

 adhesion of some part to the inner side of 

 an organ ; as when the seeds are attached 

 to the placentae, the latter are termed 

 parietal. 



PA'RIS BA'SIN. A large area, to which the 

 name of Paris Basin has been given, about 

 180 miles in length, from north-east to 

 south-west, and about ninety miles wide, 

 from east to west. The country in which 

 the capital of France is situated, is per- 

 haps the most remarkable that has yet 

 been observed, both from the succession 

 of different soils of which it is formed, 

 and from the extraordinary organic re- 

 mains which it contains. Bones of land 

 animals, of which the genera are entirely 

 unknown, are found in certain parts ; 

 other bones remarkable for their vast 

 size, and of which some of similar genera 

 exist only in distant countries, are found 

 scattered in the upper beds. Millions of 

 marine shells, which alternate regularly 

 with fresh-water shells, compose the 

 principal mass. The strata composing 

 the Paris basin rest upon chalk, lying, as 

 it were, in a depression of the chalk. 

 The depth of these strata varies from one 

 to five hundred feet. MM. Brongniart 

 and Cuvier divided the strata into the 

 five following formations, commencing 

 with the undermost. 1. First fresh- water 

 formation ; consisting of plastic clay, lig- 

 nite, and first sandstone. 2. First marine 

 formation ; comprising the calcaire gros- 

 sier. 3. Second fresh-water formation ; 

 containing siliceous limestone, gypsum, 

 with bones of animals, and fresh-water 

 marls. 4. Second marine formation ; 

 consisting of gypseous marine marls, 

 upper marine sands and sandstones, and 



