PROPIONIC 



275 



PROTOZOA 



[Propionic, q.r.]=(C.2H r) ) 2 CO=Valeric alde- 

 hyde: the ketone of propianic acid. 



Propionic acid, (pro-pi-'6'nik). [Gk. pro, first; 

 pion, fat.] = C 3 H 6 O:> = Ethyl formic acid 

 =Metacetonic acid- from fermentation of 

 glycerin, &c. ; the simplest fatty acid ; a 

 pungent crystalline substance; also called 

 Methacetic acid. 



Propionitrile, (pr5-pi-o-m'tril). [Propione and 

 Nitrile, g.v.]=C 3 H 5 N=Ethyl cyanide^Hy- 

 drocyanic ether: a colourless, alliaceous, very 

 poisonous liquid. 



Propionyl, (pro'pi-o-nil). [Propione, q.v.; Gk. 

 hyle, material.] The radicle of the propionic 

 series. 



Propodite, (pro'po-dTt)=Propodium, q.v. 



Propodium, (pro-po'di-um). [Gk. pro, front; 

 pous, foot.] The proximal segment of a Crus- 

 tacean. 



Proportion, (pro-por'shun). [Proportio, the 

 Latin word.] Equality of ratios, v. Ratio. 

 Harmonic P., v. Harmonic. 



Proposition, (prop-o-zish'un). [L. pro, forth; 

 pous, I place.] In geometry, a statement 

 put forward as truth, to be proved by refer- 

 ence to admitted truth. 



Propus, (pro'pus). A sun-stav. 



Propyl, (pr5'pil).=(C 3 H 7 )2=Hexyl hydride 

 Sextane: a liquid hydrocarbon; also called 

 Ditrityl. Isopropyl: a modification of P. 



Propylene, (pr5'pi-len). [Propyl, q.v.]=Tri- 

 tylene=Propyl=C 3 H 6 : a gas; one of the 

 ethylene series. 



Proscolex. v. Scolex. 



Prosencephalic, (pro-sen-se-fal'ik). [Gk. pro, 

 front; Cephalic, g.i>.]=Frontal: belonging to 

 the front of the cranium or forehead. 



Prosenchyma, (pros-eng 'ki-ma). [Gk. pro, 

 near; egchymos, juice.] A vegetable tissue, 

 composed of long pointed cells. 



Prosimiae, (pro-sim'i-e). [Gk. pro, near; Simia, 

 q.v.} Giebel's term for lemurs. 



Protagon, (pr5'ta-gon). [Gk. proton, first.] 

 Cii6 H 24oN4P0 2 : a solid glucoside body found 

 in the brain, from which the base neurine is 

 obtained. 



Protandry, (pro-tan'dri). [Gk. pro, before; 

 aner, man.] When the stamens of a plant 

 ripen before the pistil, cf. Protogyny. 



Protaster, (pro-tas'ter). [Gk. protos, first; 

 aster, star.] Star-fish, belonging to Ophiu- 

 roidea; known only by fossil remains found 

 in Silurian rocks. 



Proteacese, (pro-te-a'se-e). [Pro tea, the typical 

 genus.]=Proteads: shrubs and trees, with 

 hard woody leaves, belonging to Daphnales. 



Protean, (pro'te-an). [Proteus, who "was able 

 to assume various forms.] = Polymorphic : 

 having more than usual variation. 



Proteids, (pro'te-idz). [Gk. protos, first; eidos, 

 form. ] = Nitrogenous proximate principles: 

 gluten, albumen, casein, &c. : compounds of 

 oxygen, hydrogen, nitrogen, and carbon; 

 forming one of the primary divisions of food. 



Protein, ( pro'te-in ). [Gk. protos, first. ] = 

 ClsH^s^Os- HgO : the essential principle of 

 food; the only substance by means of which 

 nitrogen can be supplied to the body; exists 

 in many isomeric forms. 



Proteles, ( pro'te-lez ). [Gk. pro, in front; 

 teleos, complete. ] 

 A fox-like quad- 

 ruped, belonging to 

 Carnivora; named 

 from having five 

 digits on front feet. 

 P. ZdZdncfiissAaxd- 

 wolf. 



Proteosaurus, (pro- 

 te-o-sau'rus). [Gk. 

 protos, first ; sau- Proteles. 



ros, lizard.]=Ichthyosaurus, q.v. 



Proteus, (pro'tus). [Classical.] An elon- 

 gated urodele with permanent gills, and very 

 short legs, found in underground caves; also 

 called Siren and Hypochthon; represents the 

 larval state of the frog. 



Prothallium, ( pro-tharli-um ). [Pro and 

 Thallium, q.v.] The first development of 

 vascular cryptogamic plants. 



Protista, ( pro-tis'ta ). [Gk. protistos, very 

 first.] The lowest form of life ; microsco- 

 pical individuals, reproduced only by fis- 

 sion or gemination, considered as connect- 

 ing animals and plants, by partaking of the 

 nature of each. 



Protochlorides, (pro-to-klo'ridz). [Gk, protos, 

 first; Chloride, o.i;.]=Monochlorides, q.v. 



Protococcus, (pro-to-kok'kus). [Gk. protos, 

 first; kokkos, berry.] A microscopic plant 

 belonging to Confervaceae, q.v. P. Nivalis 

 =Red snow. 



Protogyny, (pro-toj'i-ni). [Gk. protos, first; 

 f/yne, woman.] When the pistils of a flower 

 ripen before the stamens, cf. Protandry. 



Protophyta, (pro-to-f i'ta). [Gk. protos, first; 

 phyton, plant.] v. Endlicher's. 



Protoplasm, (pro'to-plazm). [Gk. protos, first; 

 plasso, I mould.] =Physical basis of animal 

 and vegetable life: the primitive tissue of an 

 embryo. A soft, inelastic, and albuminous 

 substance which forms the intermediate 

 layer of cells; never found fluid. 



Protopteri, (pro-top'ter-i). [Protopterus, q.v.] 

 =Mudfishes=Dipnoi, q.v. 



Protopteris, (pro-top'ter-is). [Gk. protos, first; 

 pteris, fern.] A fern-like plant, known only 

 by fossil remains. 



Protopterus, (pro-top'ter-us). [Gk. protos, 

 first; pteron, fin.]=Lepidosiren, q.v. 



Protornis, (pro-tor'nis). [Gk. protos, first; 

 ornis, bird.] A sparrow-like bird, known 

 only by fossil remains, found in Eocene 

 rocks ; the oldest known fossil of this kind. 



Protorosaurus, (pro-to-ro-saw'rus). [Gk. pro- 

 tos, first ; sauros, lizard. ] = Protosauros : 

 a lizard -like animal, probably the oldest 

 known, of which fossil remains are found in, 

 Permian rocks. 



Protozoa, (pr5-to-zo'a). [Gk. protos, first ; 

 zooji, animal.] The smallest and simplest 

 animals known, forming the lowest sub- 

 kingdom of animals, including sponges, 

 rhizopods, &c. : have no special organs of 

 nutrition ; mostly secrete skeletons : also 

 considered by some naturalists to include 

 Infusoria; the only animals found in any 

 number at great sea depths. 



