ARBOR 



29 



AECTuviH 



Arbor, (ar'borJ^Axle, when small, as in a 

 watch. 



Arbor Dianas, (ar'bor di-a'ne). [L. arbor, tree; 

 Diance, of Diana.]=Silver tree, q.v., a tree- 

 like deposit of metallic silver, obtained from 

 a salt of silver. 



Arbor saturni, (ar'bor sa-tur'ni):=Lead tree, 

 q.v., analogous to silver tree. 



Arbor vitae, (ar'bor vi'te). Tree-like rami- 

 fications in the brain. 



Arborescent, (ar-bo-res'sent). [L. arbor, tree; 

 cresco, I grow.] Tree-like. 



Arboreal monkeys. [L. arbor, tree.] Having 

 the hands more or less modified into hooks, 

 with which to grasp the branches, especially 

 in Hylobates and Ateles. 



Arbutese, (ar-bu'te-e). [Arbutus, q.v.} In- 

 cludes strawberry tree, bearberry, and plants 

 belonging to Ericaceae. 



Arbutin, (ar'bu-tin). [Arbutus, g.v.]=Ci 2 Hi 6 

 Oy : a crystallised principle found in leaves 

 of bearberry. 



Arbutus, (arTju-tus). [L. arbutus, straw- 

 berry tree.] A shrub with white and red 

 flowers, belonging to Arbutese, q.v. A. unedo 

 = Strawberry tree. 



Arc, (ark). [L. arcus, a bow.] Any part of 

 a simply curved line. 



Arcanite, (ar'ka-nit). [L. 

 arcanus, hidden.] A 

 colourless variety of sul- Arc. 



phate of potash. 



Arch, (artsh). [Arc, the French word.] Any 

 structure concave below, supported at the 

 lower extremities, usually supporting a 

 weight, and bridging over a space, as a door- 

 way, window, or the arch of a bridge. Neu- 

 ral A., encloses the spinal chord; Cranial A. 

 encloses the brain ; Visceral A. encloses the 

 stomach, <fec. 



Archsegosaurus, (ar-ke-go-saw'rus). [Gk. ar- 

 chegos, first or leader; sauros, lizard.] A 

 batrachian reptile, known only by fossil re- 

 mains found in Carboniferous rocks. Pro- 

 perly Archegosaurus. 



Archaeocidaris, (ar-ke-o-sid'a-ris). [Gk. arch- 

 aois, ancient; kidaris, turban. ]=Seed-egg: a 

 turban-shaped sea-urchin, found fossil in 

 Palaeozoic rocks. 



Archaeoniscus, (ar-ke-o-nis'kus). [Gk. arch- 

 aios, ancient; oniscos, wood-louse.] A crus- 

 tacean animal, resembling the wood-louse, 

 known by fossil remains in Oolitic rocks. 



Archseopteryx, ( ar-ke-op'ter-iks ). [Gk. ar- 

 chaios, ancient; pteryx, wing.] An extinct 

 bird: fossil remains of one were found in Up- 

 per Oolite strata. A. macrura, unites rep- 

 tiles and birds, but nob so closely as does the 

 Compsognathus ; has a Saurian, feathered 

 tail. 



Archseotherium, ( ar-ke-o-the'ri-um ). f Gk. 

 archaios, ancient; therion, beast.] A pachy- 

 dermous animal known only by fossil re- 

 mains found in Lower Miocene rocks in 

 Nebraska. 



Archal, (art'shal, corruption of orchil)=Or- 

 chil=Rocella tinctoria: a lichen, from which 

 a purple colouring matter is obtained. 

 Archangel, (ark-an'jel). [Blossoming at St. 



Archimedes' Screw. 



Michael's day. ]=Angelica archangelica : a 

 tree belonging to Labiate. Yellow A.= 

 Lamium galeobdolon. White ^.=Lamium 

 album . RedA.= Stachys sylvatica. 



Archebiosis, (ar-ke-bi'o-sis). [Gk. arclie, be- 

 ginning; bios, life.]=Independent origina- 

 tion of living matter. 



Archegosaurus, (ar-ke-go-saw'riis). A batra- 

 chian reptile, fossil remains of which are 

 found in coal=Archsegosaurus, q.v. 



Archencephala, (ar-ken-sefa-la). [Gk. archos, 

 chief; egkephalos, brain.] Owen's term for 

 man, as being first in mental power. 



Archer-fish, (art'sher)=Toxotes: a fish belong- 

 ing to Squamipennae, named from its habit 

 of discharging drops of water at insects by 

 means of its tubular mouth. 



Archetype, (arTje-tip). [Gk. arche, beginning; 

 typos, pattern.] Original model or type. 



Archil, (art'shil). [Corruption of orchilla, the 

 Spanish name.] Orchil, a purple dye obtained 

 from lichens, especially from Rocella tinc- 

 toria,; also called Litmus. 



Archimedean Screw, ( ar - kim - S - de'an ). 

 [ Archimedes. J A 

 spiral tube wound 

 round an axis: the 

 archetype of the 

 screw-propeller. 



Archimulacris, ( ar- 

 kim-u-la'kris). A. 

 acadicus : the only 

 American fossil 

 cockroach, known 

 only by a wing. 



Architecture, ( ark-i-tek'tur ). [Gk. archos, 

 chief; tekton, builder.] The science and art 

 of building. 



Architrave, (ar'ki-trav). [Gk. archos, chief; 

 L. trabs, beam.]=Epistylion. 1. The beam 

 resting upon the columns, and supporting 

 the roof, sometimes represented by an arch; 

 the lower division of an entablature. 2. 

 Moulded lining on the face of jambs. 



Archivolt, ( ar'ki-volt ). [ Archivolto, the 

 Italian name.] The inner band, or mould- 

 ing of an arch; if plain = Soffit. 



Arciform, (ar'si-form). [L. arcus, form; forma, 

 shape.] Arch-like. 



Arctic, (ark'tik). [Arktikos, the Greek word.] 

 Belonging to the north. A. circle, extends 

 for 23 y round the N. pole. A. floral region, 

 marked by firs and berry trees, in Lapland, 

 Sweden, and the Alps. A. /oa;=Vulpes la- 

 gopa. A. miocene beds, in Iceland, Spitz- 

 bergen, &c. : contain fossil beeches, oaks, 

 vines, &c., proving a warmer climate to have 

 once existed there. 



Arctisca, (ark-tis'ka.) [Gk. arktos, bear.]= 



Water-bean=Tardigraaa : minute animals 



with a vermiform body and suctorial tube 



for mouth, forming a division of Arachnida. 



Arctocyon, found fossil in Eocene beds: the 



oldest known placental mammal. 



Arctomys, (ark'to-mis). [Gk. arl'tos, bear; 



mys, rat.]=Marmot of the Alps=Mus Al- 



pinus: a small burrowing rodent quadruped. 



Arctuvin, (ark-tu'vin). [Gk. arktos, bear; uva t 



berry. ]=^Hydroo^uii;one=C6H 6 Og: a crystal- 



