PHAGOCYTELLA 



1060 



PHALANX 



biology, Metschnikoff 's name for one of the motile, 

 ameboid, digestive cells of metazoans, moving from 

 place to place in the organism under the influence of 

 thermotaxis, or of what Stahl called positive trophotrop- 

 ism, when it was a question of attraction, and negative 

 trophotropism, in cases of repulsion. Pfeiffer included 

 the phenomena with that of the attraction of spermato- 

 zoids to the female cell, and other forms of sensibility 

 to chemic agents, under the general heading chemio- 

 taxis (positive or negative). Phagocytes are derived 

 from the endodermal or mesodermal tissues in all 

 animals. They are believed to englobe wrecks of larval 

 organs, degradation-products or excretion products, for- 

 eign particles, schizomycetes, hematozoa, etc. — their 

 activity varying as the logarithm of the excitation. They 

 digest the soluble parts and reject the insoluble residue. 

 They play an active part in the metamorphosis of 

 tissues and organs, in inflammation, and as prophylac- 

 tic agents. Phagocytes are fixed — endothelial cells, 

 fixed connective-tissue cells, and free — the wandering 

 cells or leukocytes. In man the colorless blood-cells, 

 as well as other kinds of cells, are credited with play- 

 ing the role of phagocytes. A large phagocytic 

 leukocyte is termed a macrophage, a small one, a 

 microphage. 



Phagocytella (fag-o-si-tel'-ah) [tyayelv, to eat, devour ; 

 cytella, dim. of kvtoc, a cell]. In biology, Metschni- 

 koff 's term for the simplest, primitive stage of a meta- 

 zoan, in which it is composed of two layers, the ectal, 

 an enveloping membrane, the other forming, by the 

 ental cells collected into a mass, a kind of parenchyma 

 composed of ameboid elements. This stage readily 

 passes into the gastrula-stage. 



Phagocytic (fag-o-sit'-ik) \$aytiv, to eat ; kvtoc, cell]. 

 In biology, of, pertaining to, or caused by phagocytes ; 

 cell-devouring ; cytophagous. 



Phagocytism (fag' -o-si-tiztn) [tyayelv, to eat ; kvtoq, a 

 cell]. In biology, the function of a phagocyte. The 

 doctrine that inflammation and other vital processes, 

 normal or abnormal, are due to phagocytes. 



Phagocytoblast (fag-o-si'-to-blast) [yayeiv, to eat; 

 kvtoq, a cell ; /JAacrdc, a germ]. A cell giving rise to 

 one or more phagocytes. 



Phagocytosis (fag-o-si-to' 'sis) \_tyayeiv, to eat ; kvtoq, 

 cell]. The destruction or taking up of microorganisms 

 or other solid elements by living cells, as by colorless 

 blood-corpuscles. This theory has been advanced by 

 Metschnikoff and others to explain immunity. It has 

 been found that if microorganisms, such as anthrax- 

 bacilli, are introduced into an insusceptible animal, some 

 of them will be found within the bodies of leukocytes, 

 while this does not occur in a susceptible animal. This 

 fact has led to the enunciation of the doctrine that immu- 

 nity or susceptibility depends on the ability or inability, 

 respectively, of the body-cells to destroy microorgan- 

 isms. Immunity may be congenital or acquired ; in 

 the latter case it is brought about by an adaptation of 

 the cells to the end that they can consume virulent 

 organisms without harm. Several arguments have been 

 advanced against Metschnikoff 's views. It has been 

 said that the bacteria sometimes found in leukocytes 

 are probably dead ; if a living microorganism enters a 

 colorless blood-corpuscle, the latter is more likely 

 to suffer than the former. Again, the symptoms 

 of infectious diseases are due to pecidiar poisons rather 

 than to the bacteria as such. Immunity can be con- 

 ferred upon an animal by injections of appropriate 

 doses of such poisons, a fact that cannot readily be 

 explained by the phagocytic theory. It has also been 

 demonstrated that the blood-serum possesses bacteri- 

 cidal properties, and that the blood-serum of artificially 

 immune animals is capable of immunizing other ani- 



mals, and if given in sufficient strength and dose, even 

 of arresting the disease when already established. The 

 tendency at present is to ascribe the causation of immu- 

 nity to a peculiar property of the body-fluids — whether 

 bactericidal or antitoxic in nature, i. e., counteracting 

 the bacterial poison ; this is not fully established. 



Phagomania (fag-o-ma'-ne-ah) \jj>ayelv, to eat; /uavia, 

 madness]. An insatiable craving for food. 



Phagosite (fag'-o-slt) [(payeiv, to eat; o'itoq, food]. 

 An animal organism that feeds on but does not dwell 

 within or on its host, e. g., the leech, lamprey, camel- 

 tick, Vampire bat. 



Phakitis (fa-ki'-tis) [<pan6g, lens ; ltlq, inflammation]. 

 Hypothetically, inflammation of the crystalline lens of 

 the eye ; practically, however, no such condition has 

 been observed. 



Phakometer (fa-kom'-et-er) [_<panoQ, lens; / 

 measure]. An instrument for measuring the curva- 

 tures and refractive powers of lenses. 



Phakosclerosis (fa-ko-skle-ro' -sis) \Jmk6q , lens ; 

 p6q, hard]. Induration or hardness of the crystalline 

 lens. 



Phakoscope (fa' ' -ko-skop) \_§clk6q, lens ; gkotteId, to 

 see]. An instrument for observing and estimating the 

 change in the shape of the crystalline lens produced by 

 accommodative influences. 



Phalacra, Phalacrosis (fal'-ak-rah, fal-akro'-sis) 

 \q>a'ha,Kp6g, bald]. Baldness. 



Phalacroma (fal-ak-ro' -mah). Synonym of Phalac- 

 rosis. 



Phalangagra (fa-lang-ga' -grah). Synonym of Phalan- 

 garthritis. 



Phalangal (fa-lang' '-gal). Same as Phalangeal. 



Phalangarthritis (fa-lang-gar-thri' '-tis) [yalayl; , pha- 

 lanx ; apOpov, joint; itiq, inflammation]. Inflam- 

 mation of phalangeal joints. 



Phalange (fa-lanf) [aaXay!;, the bone of a finger or 

 toe]. In biology : (a) one of the bones of a finger or 

 toe; (l>) one of the joints of an insect's tarsus; (c 

 a bundle of stamens united by their filaments. 



Phalangeal (fa-lan' '-je-al) \$a\ay%, phalanx]. Per 

 taining to a phalanx, or to phalanges. P. Bone, a 

 phalanx. P. Process, in biology : (a) a slender 

 prolongation of Deiter's cells attached to the phalanx 

 of the reticular lamina of the organ of Corti ; (i) the 

 external process of the head of an outer rod of Corti. 



Phalangean (fa-lan' -je-an). Same as Phalangeal. 



Phalanges (fa-lan' -jez) \j>cT/.ay^, phalanx]. Plural 

 of Phalanx. P. of Ear, the minute cuticular 

 in the organ of Corti. 



Phalangette, Phalanget (fal-an-jef) [Fr.]. The third 

 phalanx or terminal bone of the finger. 



Phalangial, Phalangian (fa-Jan' '-je-al, fa-lan'- 

 Same as Phalangeal. 



Phalangic (fa-lan' -jik). Synonym of Phalai 



Phalangiform (fa-lan' -jif-orm) [(pdXay^, phalanx ; 

 forma, form]. Having the shape of a phalanx. 



Phalangigrade (fa-lan' -jig-rad) [0d/.«yf, phalanx; 

 gradi, to go]. In biology, walking on the phal 



Phalangine (fal'-an-jin) [Fr.]. The second phalanx 

 or second bone of the finger. 



Phalangitis ( fa-lan- ji f -tis) [4>a?.ayi;, phalanx ; 

 inflammation]. Inflammation of a phalanx. 



Phalango-phalangeal (fa-lan' '-go-fa-lan'-je-aJ} 

 lay%, phalanx]. Pertaining to the successive phal 

 of the digits. P. Amputation, removal of a fn 

 or toe at the first or second phalangeal joints. 



Phalangosis (fal-an-go'-sis) [<ba?.ayZ, phalanx]. I. • 

 disease of the eyelids in which the lashes U 

 ranged in rows. 2. Ptosis. 



Phalanx (fa' -tanks) [<t>d?Myt, phalanx : pi. , Phalanges 

 Any one of the bones of the fingers or toes. P- 



