PET 



315 



PHA 



pistillum, the pestle of a mortar), 

 any heavy article for pounding 

 and mixing substances in a 

 mortar: pestillation, n., pZst'il- 

 laf'Shun, the act of pounding in a 

 mortar. 



petal, n., pVt'al (Gr. petalon> a 

 leaf), in ktf, the leaf of an ex- 

 panded flower; one of the separate 

 parts of a corolla or flower : 

 petaline, a., pH'-al-ln, of or pert, 

 to a petal : petalody, n,, pet-al'- 

 dd-i (Gr. eidos, resemblance), a 

 state in which sepals become 

 coloured like petals ; the conver- 

 sion of parts of the flower into 

 petals : petaloid, a., petal- oyd 

 (Gr. eidos, resemblance), having 

 the appearance or colour of a 

 petal ; in zooL, shaped like the 

 petal of a flower : petaloidese, n. 

 plu. ,p$tftil'dfyd''%-f) a term applied 

 to a sub-class of plants whose 

 flowers have usually a perianth 

 consisting either of verticillate 

 leaves, or of a few whorled scales, 

 in the former case sometimes 

 separable into calyx and corolla, 

 and often coloured, 

 petechiae, n. plu., %&$&%$ (It. 

 petecchie), in med., purple or 

 dark-red spots which appear on 

 the skin when there is much dis- 

 order in the blood, as in fevers of 

 a malignant type : petechial, a., 

 pU'etf'i'al) of or connected with 

 diseases having the characterist- 

 ics of petechise, as 'petechial 

 plague. ' 



petiole, n., petrol (L. petiftluS) a 

 little foot from pes, a foot), in 

 bot., the footstalk of a leaf con- 

 necting the blade with the stem : 

 petiolar, a., p$t'i'dl'ar t also 

 petiolary, a., p^t-i'dl-dr-i, pert. 

 to or growing on a small stalk ; 

 having a stalk or petiole : petiol- 

 ate, a., pZt-i'.dl-dt, growing on a 

 petiole : petiolule, n., pet-i'-Sl-til, 

 the stalk of a leaflet in a com- 

 pound leaf. 



PetiverieaB, n. plu., pWl>v%r>i'%> 

 (after Petivtr, a London apothe- 



cary), a Sub-order of plants hav- 

 ing erect seeds, Ord. Phytolac- 

 cacese: Petiveria, n., pZt'iv-er' 

 i' a, a genus of ornamental plants: 

 Petiveria alliacea, aKli-a'-sZ-a, 

 (L. allmm, garlic), the guinea- 

 hen-weed, so named from these 

 animals being partial to it. 

 Petroselinum, n^p^rd-s 

 (Gr. petros, a rock ; 

 parsley), a genus of plants, Ord. 

 llmbelliferse : Petroselinum sat- 

 ivum, sat'iv'um (L. sativum, 

 that is sown or planted), common 

 parsley. 



petrous, a., p&'rtis (L. petrosus, 

 full of rocks faoiQ-petra, a stone), 

 hard ; stony ; in anat. , applied 

 to a dense, solid mass of bone, 

 forming a part of the temporal 

 bone ; designating a ganglion 

 situated in the lower border of 

 the petrous portion of the tem- 

 poral bone : petrosal, a, p^t-rdz- 

 dl t in same sense as ' petrous ' ; 

 the ear-capsule bone in a fish : 

 petrosal nerve, a branch of the 

 Vidian nerve : petro - occipital, 

 p^t'-rd - tik'Sip'-it'Cilt connected 

 with the petrous portion of the 

 temporal bone, and with the 

 occipital bone. 



phsenogamous, . a., f en-tig' am-tts 

 (Gr. phaino, I show, I manifest ; 

 gamoS) marriage), in bot t > having 

 conspicuous flowers. 

 Phseosporese, n, plu.,ye*0-spor'g-e 

 (Gr. phaioS) dusky; spora t seed), 

 in bot^ a division of Melano- 

 spore?e, or olive-colottred sea- 

 weeds, which possess zoospores ; 

 Algae having an olive-green or 

 olive -brown colour, and cellular 

 or filamentous structure, 

 phagedaBna, n., fadj''8d>en'>a (Gr. 

 phago t I devour, I gnaw), a 

 variety of ulceration wnich de- 

 stroys the tissues more rapidly, 

 and to a greater extent, than 

 ordinary forms of ulcer ; gan- 

 grenous ulceration. 

 phaiophyll, n. Jl^o-fll (Gr. phaios, 

 brown ; phullon, a leaf), a group 



