PAL 



PAP 



applied tq the minute colourless bracts 

 at the base of the florets of a capituluni ; 

 and to the floral envelope of grasses, 

 which immediately surrounds the sexual 

 organs. 



Paleaceous. Chaff"y ; covered with pa- 

 leae, or membranous scales, as the recep- 

 tacle of some compositas. 



PALLADIUM. A new metal found 

 by WoUaston in the ore of platinum. 



PALLAS or OLBERS. A telescopic 

 planet, discovered by Dr. Olbers, in 1802, 

 and situated in the solar system between 

 Mars and Jupiter. Its diameter is un- 

 known. It describes its orbit round the 

 sun in four years, seven months, and 

 eleven days. Its distance from the sun 

 is 267 millions ef miles. 



PA'LLIAL IMPRESSION. The mark 

 formed in a bivalve shell by the pallium 

 or mantle. It occurs usually near the 

 margin of the shell, and is, hence, some- 

 times called the marginal impression. In 

 the Dimyaria, this mark passes from one 

 impression of the muscles of attachment 

 to the other ; if, in its passage, it bends 

 inwards posteriorly, it is said to be smu- 

 ated, and the part where this occurs is 

 the siphonal scar of Mr. Gray. 



PA'LLIOBRANCHIA'TA {pallium, a 

 mantle, branchiee, gills). A term ori- 

 ginally proposed by Blainville for the 

 JBrachiopodous mollusca, notwithstanding 

 his belief that the spiral arms were the 

 organs of respiration. It has since been 

 proved by Owen to be strictly appropriate, 

 and is applied by him to the class of ace- 

 phalous mollusca, in which the gills are 

 developed from the mantle. 



PALMA'CEiE. The Palm tribe of 

 Monocotyledonous plants. Plants with 

 an arborescent trunk, covered with the 

 sheathing bases of leaves ; leaves termi- 

 nal, clustered, pinnate, or flabelliform ; 

 flowers hexapetaloideous, stamens defi- 

 nite; ovarium superior, 3-celled; fruit 

 baccate, or drupaceous, with fibrous 

 flesh. 



PALMATE LEAF. A form of leaf, 

 having five lobes, with the midribs radi- 

 ating from a common point at the base of 

 the leaf, and resembling the palm of the 

 hand. The palmate leaf admits of the 

 following varieties, which occur, in bota- 

 nical descriptions : — 



1. Palmatifid, in which the lobes are 

 divided as far down as half the breadth 

 of the leaf. 



2. Palmatilohaie, in which the lobes 

 are divided to an uncertain depth, 



3. Palmatipartite, in which the lobes 



247 



are divided beyond the middle, and the 

 parenchyma is not interrupted. 



4. Palmatisected, in which the lobes 

 are divided down to the midrib, and the 

 parenchyma is interrupted. 



PALMI'PEDES (palma, the palm of 

 the hand, pes, the foot). Natatores. 

 Swimmers ; an order of web-footed birds, 

 capable of swimming in the water the 

 instant they are liberated from their egg- 

 coverings. They comprehend the divers, 

 pelicans, albatrosses, swans*, &c. 



PA'LPI {palpo, to touch). The organs 

 of touch developed from the labium and 

 maxillae of insects, commonly called 

 feelers. 



PALPICO'RNES (pa^ij/, feelers, cornu, 

 a horn). A family of the pentamerous 

 Coleoptera, characterized by the presence 

 of antennae with club-like terminations, 

 which are usually shorter than one of the 

 pairs of palpi. They are mostly aquatic. 



PANDURIFORM {pandura, the an- 

 cient shepherd's pipe, forma, likeness). 

 Fiddle-shaped ; obovate, with a deep 

 sinus on each side, as the leaves of rumex 

 pulcher. 



PA'NGOLINS. A common designa- 

 tion of the Scaly Ant-eaters, derived 

 from a Javanese word signifying an ani- 

 mal which rolls itself into the form of a 

 ball. The pangolins correspond with the 

 genus Manis of Linnaeus. 



PANICLE {panicula, the woof wound 

 round the quill in the shuttle). A form 

 of inflorescence, in which the flower-buds 

 of a raceme have, in elongating, developed 

 other flower-buds, as in the oat. When 

 the rachis of inflorescence separates irre- 

 gularly into branches, so as to lose the 

 form of an axis, this is called by Willde- 

 now a deliquescent panicle. 



PANTOCHRONO'METER (Trat, irav- 

 Top, all, xpovoi, time, /xerpov, a measure). 

 An instrument which combines the use 

 of the compass, of the sun-dial, and of 

 the universal time-dial. 



PAPAVERACE^. The Poppy tribe 

 of Dicotyledonous plants. Herbaceous 

 plants with leaves divided, alternate ; 

 flowers polypetalous, single on long pe- 

 duncles ; petals 4, or some multiple of 4, 

 cruciate ; stamens hypogynous ; ovarium 

 solitary ; seeds numerous. 



PAPER COAL. A bituminous shale, 

 which separates into thin laminae of 

 coal, like sheets of paper. 



PAPILIONACEOUS (papilio, a but- 

 terfly). A form of corolla resembling a 

 butterfly, and found in all the leguminous 

 plants of Europe. Of the five petals, the 

 M4 



