ARCHIGONY 



91 



ARECOLIN 



/-.higony. See Archegony (Illus. Diet.). 

 /;himorphic \ar-ke-morf'-ik) [dp^oc , a chief ; fiopQrj, 

 ne form]. Dominant by virtue of superiority. A. 

 laces, the dominant active races ; civilized races 

 . rvoiker). 

 /:hineuron (ar-ke-nu'-ron) \_ap\ij, beginning; vev- 

 erve]. I. A primitive neuron. 2. The neu- 

 >n at which the impulse starts in any physiologic act 

 ig the nervous system. 

 e hitype [ar'-ke-tip). See Archetype. 

 A hocystosyrinx i ar-ko-sist-o-sir / -htks) [dpjoc, anus ; 

 bladder; cvptyz, fistula]. A retrovesical fis- 

 ila. 

 A hoplasm, Archoplasma {ar f -ko-plazm, ar-ko-plaz'- 

 i.)\uv, a ruler; -/arrua, a thing formed]. 

 - term for the substance from which the attrac- 

 Dn-sphere, the astral rays, and the spindle-fibers 

 mitosis are derived and of which they consist ; also 

 illed Kinoplasm. 

 A hyle \ar-ki'-le) [apx'l* a beginning; v/.r/, matter]. 



ie Protyle (Illus. Diet.). 

 A ocele \ar'-ko-sel). See Archocele (Illus. Diet.). 

 A tation. See Illus. Diet. ) 3. Constipation ; con- 



riction. 



A tura [ark-tu'-rah) \_arctus, pressed close together]. 



The condition resulting from an ingrowing nail. 



.n.. A. unguis, A. unguium; Onychosis arctura. 



See Arctation (Illus. Diet.). 



A turin ark'-tu-rin . A bitter substance obtained 



jm arbutin. 

 A tuvein, Arctuvin [ark-tu'-ve-in, ark'-tu-ziti). A 

 e derived from arbutin by action of sulfuric 

 \ith heat. 

 Aula \ark'-u-lah) \_arcula, a casket]. The orbit. 



. cordis, the pericardium. 

 Ajus. Set- Illus. Diet.) A. atlantis anterior. 

 ;e Arch of the Atlas. Anterior. A. atlantis pos- 

 rior. See Arch of the Atlas, Posterior. A. faucium, 

 . glossopalatinus. See Arch, Palatine. A. med- 

 ians. See Fornix (Illus. Diet.). A. senilis 

 ntis. See Cataract, Incipient. A. tendineus. 

 \te line (of pelvic fascia) (Illus. Diet.). A. 

 iguium. See Lunula (Illus. Diet.). A. vasculosi 

 nales, arches at the bases of the Malpighian pyra- 

 ■ ids, formed by anastomoses of tiny ramifications of 

 e renal artery. They give off vessels supplying the 

 rtex of the kidneys, the Malpighian corpuscles, and 

 e capillary plexuses about the uriniferous tubules, 

 j'n., Fornices vasculosi renum. 



See Illus. Diet.) 2. Applied by Celsus to any 



rm ot baldness. A., Alisphenoid, the surface of 



e great wing of the sphenoid. A., Anesthetic, a 



>t the body naturally destitute of sensory 



one which has become abnormally anesthetic. 



., Anteroparietal, the outer surface of the parietal 



ne lying in front of the parietal eminence. A., 



uditory, the cerebral center for hearing. A., 



roca's, the medial portion of the anterior olfactory 



Syn. , A. parolfactoria : Gyrus olfactorius 



A., Broca's Olfactory, the posterior end 



the gyrus rectus lying anteriorly to the mesial root 



the olfactory tract. Syn., Trigonum olfactorium. 



Catchment, the district or water-shed over which 



: rainfall is impounded for purposes of water-supply. 



• Cord, that part of the cortex in which lesions 



Id produce degeneration of the spinal cord. A. 



ibrosa. See Macula cribrosa Tllus. Diet.). A., 



u f***. See Space, Interpeduncular. A., Crypt, in 



lection of crypts the area surrounding one of the 



A. diffluens, alopecia areata. A., Diffrac- 



'n. a clear area seen in the microscopic image around 



bodies of greater or less refractive power, and 



which by Xageli and Schwendener was referred partly 

 to the direct reflection of the incident light at the edge 

 of the body in question, partly to the interference of 

 this reflected light which comes through unreflected. 

 [Biitschli] A., Fetal, A., Germ, A., Germinal. 

 See A. gertninativa (Illus. Diet. f. A., Frontal, the 

 convex surface of the frontal bone. A., Frontopar- 

 ietal, that included in the frontal lobe of the cere- 

 brum and the ascending parietal gyrus. A., Glove, an 

 area of anesthesia observed in cases of multiple neu- 

 ritis embracing hand and wrist. A., Intercalated. 

 See A., Xonnucleated. A., Intercrural. See Space, 

 Interpeduncular 1 Illus. Diet.). A. johnstoni ( ]oh.). 

 Sec/., Celsus (Illus. Diet.). A., Martegiani's, the 

 slight widening of the hyaloid canal at its beginning in 

 front of the optic disk. A., Midfrontal, the mesal 

 portion of the frontal area. A.. Motor, the gyri on 

 each side of the Rolandic fissure containing the cen- 

 ters for voluntary motion. A., Nonnucleated, one 

 of the clear spaces found at times between the endo- 

 thelial cells of blood-vessels ; they have no nuclei, are 

 smaller than endothelial cells, and are considered to 

 be due to the removal of parts of the surrounding en- 

 dothelium. A. nummulata,*coin-shaped patches of 

 alopecia areata. A., Occipital, the portion of the 

 brain below the occiput. A., Opaque. See A. 

 optica (Illus. Diet.). A., Parietal, the part of the 

 brain below the parietal bone. A., Placental, that 

 part of the uterine wall to which the placenta is at- 

 tached. A., Posteroparietal, the part of the exter- 

 nal surface of the parietal bone lying behind the pari- 

 etal eminence. A., Rolandic, the excitomotor area 

 of the cerebral hemispheres, comprising the ascending 

 frontal and ascending parietal convolutions. A., Sep- 

 tal, the inner surface of each of the laminas which 

 make up the septum lucidum. A., Serpens. See 

 Ophiasis (Illus. Diet.). A. serpiginosa, alopecia 

 areata with a tendency to spread peripherally. A., 

 Spencer's, a cortical area in the frontal lobe just out- 

 side of the olfactory tract and anterior to the point 

 where it joins the temporosphenoid lobe, as indicated 

 by the crossing of the Sylvian artery. Faradic stimu- 

 lation of this area influences the respirator}- move- 

 ments, causing stoppage of the respiration when suffi- 

 ciently intense. A., Superofrontal, the upper part 

 of the frontal area. A., Transparent. See A. pet- 

 lucida (Illus. Diet.). A. ventriculi quarti, the floor 

 of the fourth ventricle. A.s, Viscerocutaneous, 

 areas of skin and viscera corresponding to different 

 spinal segments, useful in electrotherapy. A., Visual, 

 the occipital lobe and the angular gyrus. A., vitel- 

 lina. the yolk area outside the area vasculosa in meso- 

 blastic eggs. A., Vocal, the portion of the glottis 

 lying between the vocal bands. 



Areca iar-e'-kah). A genus of East Indian palms. 

 A. catechu is extensively distributed throughout the 

 tropics of Asia, where it has been cultivated from 

 earliest times. It furnishes the betel-nut (</. v. ) ; the 

 powdered nut is used as a vermifuge. 



Arecaidin (ar-e-£a'-id-in). CjHjjNO,. An acid 

 contained in areca-nut, of which arecolin is its methyl 

 ether. 



Arecain (ar-e'-ka-in). C ; H u NO., + H 2 0. A poison- 

 ous teniacidal alkaloid obtained from areca-nut. form- 

 ing colorless crystals soluble in water, insoluble in 

 alcohol, in ether, and in benzol. 



Arecolin. (See Illus. Diet.) A. Hydrobromate, 

 C^HjjXOjHBr, white crystals soluble in water and 

 alcohol. It is used as a myotic, applied in i c / c solu- 

 tion, and in treatment of glaucoma. In veterinary 

 practice it is used as a cathartic and anthelmintic. In- 

 jection for horse, }4—l gr. 



