PHY 



PHY 



the heat produced by the absorption of 

 light. 



PHRA'GMOCONE {(ppdyna, a parti- 

 tion, Kttivof, a cone). The chambered 

 cone of the shell of the Belemnite. 



PHRASE (in Music). This term is 

 defined by Rousseau as a succession of 

 sounds in melody or harmony, expressing 

 an unbroken sense more or less complete, 

 and terminating in a pause, thus forming 

 a cadence more or less perfect. But the 

 notions entertained of this term are 

 various. 



PHRENO'LOGY {<ppriv, the mind, 

 Aoyof, an account). The name of a 

 science introduced by Gall and Spurz- 

 heim, by which particular characters and 

 propensities are indicated by the con- 

 formation and protuberances of the skull. 



PHYCOMA'TER {^Ckop, sea-weed, 

 Hrjrnp, mother). The name given by 

 Fries to the gelatine in which the sporules 

 of byssaceous plants first vegetate. 



PHYLLI'DIANS. The name given 

 by Lamarck to a family of Gasteropodous 

 molluscs, typified by the genus phyllidia, 

 and characterized by the position of the 

 branchia in a circle round the body be- 

 tween the foot and the mantle. 



PHYLLO'DIUM (<pv\\ov, a leaf). A 

 term applied to the petiole of a leaf, 

 when it is expanded and leafj', and the 

 lamina abortive, as in many species of 

 Acacia. 



PHYLLONY'CTERANS i<pv\\ov, a 

 leaf, vvKrepk, a bat). A primary division 

 of the Cheiroptera, commonly termed the 

 "foliated bats," from the peculiar mem- 

 branous foliations which in these animals 

 serve the purpose of antenna?. 



PHYLLO'PODA (<pv\\ov, a leaf, ttovc, 

 n-o36f, a foot). An order of the bran- 

 chiopodous Crustacea, in which the body 

 is elongated, and the extremities flattened 

 for the purpose of swimming, as in the 

 branchipus. 



PHYLLOSO'MA {<pv\\ov, a leaf, awfia, 

 the body). The family of double-cuirassed 

 crustaceans, the forms of which are re- 

 markable for their rounded shape and 

 the transparency of their integuments. 



PHYLLOSTOMI'NiE {<p6\\ov, a leaf, 

 aroixa, the mouth). A family of insec- 

 tivorous Cheiroptera, which have the 

 nasal appendage simple and fleshy, and 

 to which the celebrated vampyre belongs. 

 PHY'SALITE. Pyrophysalite. A sub- 

 species of prismatic topaz, found in 

 granite at Finbo in Sweden. 



PHYSCOSTE'MON (</.i;(Tcia), to swell, 

 aT>7/uft)i/, a stamen). The name given by 

 259 



Turpin to a fleshy body found in certain 

 plants between the base of the stamens 

 and the base of the ovary. It is com- 

 monly called the disk. 



PHYSICAL DEFINITION. A defi- 

 nition which assigns the parts into 

 which the thing defined can be actually 

 divided. Thus, a plant would be defined 

 physically, by enumerating the root, 

 stalk, leaves, &c., of which it is com- 

 posed. Logically, it would be defined 

 " an organized being, destitute of sensa- 

 tion," the former of these expressions Aq- 

 xxotmgihQ genus, the latter the difference, 



PHY'SICS ((pvarii, nature). That de- 

 partment of science which treats of the 

 properties of bodies, the laws of motion, 

 and the general phenomena of nature. 

 It is commonly termed Natural Philoso- 

 phy and Mechanical Philosophy. Bacon 

 endeavours to draw a line between phy- 

 sics and metaphysics ; — " Physic is that 

 which inquires of the efficient cause and 

 of the matter ; metaphysic, that which 

 inquires of the form and end." 



PHYSIO'GNOMY (^ucrio-yvw/iov/a). 

 The science or art of judging of a per- 

 son's character by his outward look. 



PHYSIOLOGY {(piaii, nature, Xd'yor, 

 an account). The science which treats 

 of the properties of organic bodies, ani- 

 mal and vegetable ; of the phenomena 

 which they present ; and of the laws 

 which govern their actions. 



PHYSO'GRADA. An order of the 

 Acalephce, in which the body is supported 

 in the water by means of one or more 

 bladders, capable of being filled with air 

 at the will of the animal, and which, 

 when partially empty, enable the animal 

 to sink on the approach of danger. These 

 are the hydrostatic acalephce of Cuvier. 

 M. de Blainville considers the Physo- 

 grada as one of the aberrant or false 

 forms of the Zoophytes, and as animals 

 improperly referred to them. 



PHYTO'GRAPHY {<(>vr6v, a plant, 

 fpa.<p(a, to write). An account of the 

 rules observed in describing and naming 

 plants. 



PHYTO'LOGY (0i;tov, a plant, Xoyor, 

 an account). That branch of science 

 which treats of the forms and properties 

 of plants. 



PHYTOTHAGOUS (0uToy, a plant, 

 00170), to eat). Plant-eating ; a terra ap- 

 plied to a division of cetaceous animals, 

 and to a tribe of plant-eating gasteropods. 

 See Zoophagous. 



PHYTO'TOMY (0ut6»/, aplant, re^vu), 

 to cut). Vegetable anatomy ; the display 



