s　convinced　that　he　understood　a　smile　and　received　pleasure　from　seeing　one；　answering　it　by　another；　at　much　too　early　an　age　to　have　learnt　anything　by　experience。　　When　this　child　was　about　four　months　old；　I　made　in　his　presence　many　odd　noises　and　strange　grimaces；　and　tried　to　look　savage；　but　the　noises；　if　not　too　loud；　as　well　as　the　grimaces；　were　all　taken　as　good　jokes；　and　I　attributed　this　at　the　time　to　their　being　preceded　or　accompanied　by　smiles。　　When　five　months　old；　he　seemed　to　understand　a　compassionate；　expression　and　tone　of　voice。　When　a　few　days　over　six　months　old；　his　nurse　pretended　to　cry；　and　I　saw　that　his　face　instantly　assumed　a　melancholy　expression；　with　the　corners　of　the　mouth　strongly　depressed；　now　this　child　could　rarely　have　seen　any　other　child　crying；　and　never　a　grown…up　person　crying；　and　I　should　doubt　whether　at　so　early　an　age　he　could　have　reasoned　on　the　subject。　Therefore　it　seems　to　me　that　an　innate　feeling　must　have　told　him　that　the　pretended　crying　of　his　nurse　expressed　grief；　and　this　through　the　instinct　of　sympathy　excited　grief　in　him。
  ＇2＇　‘La　Physionomie　et　la　Parole；'　1865；　pp。　　103；　118。
  ＇3＇　Rengger；　‘Naturgeschichte　der　Saugethiere　von　Paraguay；'　1830；　s。　　55。
  M。　Lemoine　argues　that；　if　man　possessed　an　innate　knowledge　of　expression；　authors　and　artists　would　not　have　found　it　so　difficult；　as　is　notoriously　the　case；　to　describe　and　depict　the　characteristic　signs　of　each　particular　state　of　mind。　But　this　does　not　seem　to　me　a　valid　argument。　We　may　actually　behold　the　expression　changing　in　an　unmistakable　manner　in　a　man　or　animal；　and　yet　be　quite　unable；　as　I　know　from　experience；　to　analyse　the　nature　of　the　change。　In　the　two　photographs　given　by　Duchenne　of　the　same　old　man　（Plate　III。　　figs。　　5　and　6）；　almost　every　one　recognized　that　the　one　represented　a　true；　and　the　other　a　false　smile；　but　I　have　found　it　very　difficult　to　decide　in　what　the　whole　amount　of　difference　consists。　　It　has　often　struck　me　as　a　curious　fact　that　so　many　shades　of　expression　are　instantly　recognized　without　any　conscious　process　of　analysis　on　our　part。　No　one；　I　believe；　can　clearly　describe　a　sullen　or　sly　expression；　yet　many　observers　are　unanimous　that　these　expressions　can　be　recognized　in　the　various　races　of　man。　　Almost　everyone　to　whom　I　showed　Duchenne's　photograph　of　the　young　man　with　oblique　eyebrows　（Plate　II。　　fig。　　2）　at　once　declared　that　it　expressed　grief　or　some　such　feeling；　yet　probably　not　one　of　these　persons；　or　one　out　of　a　thousand　persons；　could　beforehand　have　told　anything　precise　about　the　obliquity　of　the　eyebrows　with　their　inner　ends　puckered；　or　about　the　rectangular　furrows　on　the　forehead。　So　it　is　with　many　other　expressions；　of　which　I　have　had　practical　experience　in　the　trouble　requisite　in　instructing　others　what　points　to　observe。　　If；　then；　great　ignorance　of　details　does　not　prevent　our　recognizing　with　certainty　and　promptitude　various　expressions；　I　do　not　see　how　this　ignorance　can　be　advanced　as　an　argument　that　our　knowledge；　though　vague　and　general；　is　not　innate。
  I　have　endeavoured　to　show　in　considerable　detail　that　all　the　chief　expressions　exhibited　by　man　are　the　same　throughout　the　world。　This　fact　is　interesting；　as　it　affords　a　new　argument　in　favour　of　the　several　races　being　descended　from　a　single　parent…stock；　which　must　have　been　almost　completely　human　in　structure；　and　to　a　large　extent　in　mind；　before　the　period　at　which　the　races　diverged　from　each　other。　No　doubt　similar　structures；　adapted　for　the　same　purpose；　have　often　been　independently　acquired　through　variation　and　natural　selection　by　distinct　species；　but　this　view　will　not　explain　close　similarity　between　distinct　species　in　a　multitude　of　unimportant　details。　Now　if　we　bear　in　mind　the　numerous　points　of　structure　having　no　relation　to　expression；　in　which　all　the　races　of　man　closely　agree；　and　then　add　to　them　the　numerous　points；　some　of　the　highest　importance　and　many　of　the　most　trifling　value；　on　which　the　movements　of　expression　directly　or　indirectly　depend；　it　seems　to　me　improbable　in　the　highest　degree　that　so　much　similarity；　or　rather　identity　of　structure；　could　have　been　acquired　by　independent　means。　Yet　this　must　have　been　the　case　if　the　races　of　man　are　descended　from　several　aboriginally　distinct　species。　　It　is　far　more　probable　that　the　many　points　of　close　similarity　in　the　various　races　are　due　to　inheritance　from　a　single　parent…form；　which　had　already　assumed　a　human　character。
  It　is　a　curious；　though　perhaps　an　idle　speculation；　how　early　in　the　long　line　of　our　progenitors　the　various　expressive　movements；　now　exhibited　by　man；　were　successively　acquired。　　The　following　remarks　will　at　least　serve　to　recall　some　of　the　chief　points　discussed　in　this　volume。　We　may　confidently　believe　that　laughter；　as　a　sign　of　pleasure　or　enjoyment；　was　practised　by　our　progenitors　long　before　they　deserved　to　be　called　human；　for　very　many　kinds　of　monkeys；　when　pleased；　utter　a　reiterated　sound；　clearly　analogous　to　our　laughter；　often　accompanied　by　vibratory　movements　of　their　jaws　or　lips；　with　the　corners　of　the　mouth　drawn　backwards　and　upwards；　by　the　wrinkling　of　the　cheeks；　and　even　by　the　brightening　of　the　eyes。
  We　may　likewise　infer　that　fear　was　expressed　from　an　extremely　remote　period；　in　almost　the　same　manner　as　it　now　is　by　man；　namely；　by　trembling；　the　erection　of　the　hair；　cold　perspiration；　pallor；　widely　opened　eyes；　the　relaxation　of　most　of　the　muscles；　and　by　the　whole　body　cowering　downwards　or　held　motionless。
  Suffering；　if　great；　will　from　the　first　have　caused　screams　or　groans　to　be　uttered；　the　body　to　be　contorted；　and　the　teeth　to　be　ground　together。　But　our　progenitors　will　not　have　exhibited　those　highly　expressive　movements　of　the　features　which　accompany　screaming　and　crying　until　their　circulatory　and　respiratory　organs；　and　the　muscles　surrounding　the　eyes；　had　acquired　their　present　structure。　　The　shedding　of　tears　appears　to　have　originated　through　reflex　action　from　the　spasmodic　contraction　of　the　eyelids；　together　perhaps　with　the　eyeballs　becoming　gorged　with　blood　during　the　act　of　screaming。　　Therefore　weeping　probably　came　on　rather　late　in　the　line　of　our　descent；　and　this　conclusion　agrees　with　the　fact　that　our　nearest　allies；　the　anthropomorphous　apes；　do　not　weep。　But　we　must　here　exercise　some　caution；　for　as　certain　monkeys；　which　are　not　closely　related　to　man；　weep；　this　habit　might　have　been　developed　long　ago　in　a　sub…branch　of　the　group　from　which　man　is　derived。　Our　early　progenitors；　when　suffering　from　grief　or　anxiety；　would　not　have　made　their　eyebrows　oblique；　or　have　drawn　down　the　corners　of　their　mouth；　until　they　had　acquired　the　habit　of　endeavouring　to　restrain　their　screams。　The　expression；　therefore；　of　grief　and　anxiety　is　eminently　human。
  Rage　will　have　been　expressed　at　a　very　early　period　by　threatening　or　frantic　gestures；　by　the　reddening　of　the　skin；　and　by　glaring　eyes；　but　not　by　frowning。　　For　the　habit　of　frowning　seems　to　have　been　acquired　chiefly　from　the　corrugators　being　the　first　muscles　to　contract　round　the　eyes；　whenever　during　infancy　pain；　anger；　or　distress　is　felt；　and　there　consequently　is　a　near　approach　to　screaming；　and　partly　from　a　frown　serving　as　a　shade　in　difficult　and　intent　vision。　It　seems　probable　that　this　shading　action　would　not　have　become　habitual　until　man　had　assumed　a　completely　upright　position；　for　monkeys　do　not　frown　when　exposed　to　a　glaring　light。　　Our　early　progenitors；　when　enraged；　would　probably　have　exposed　their　teeth　more　freely　than　does　man；　even　when　giving　full　vent　to　his　rage；　as　with　the　insane。　We　may；　also；　feel　almost　certain　that　they　would　have　protruded　their　lips；　when　sulky　or　disappointed；　in　a　greater　degree　than　is　the　case　with　our　own　children；　or　even　with　the　children　of　existing　savage　races。
  Our　early　progenitors；　when　indignant　or　moderately　angry；　would　not　have　held　their　heads　erect；　opened　their　chests；　squared　their　shoulders；　and　clenched　their　fists；　until　they　had　acquired　the　ordinary　carriage　and　upright　attitude　of　man；　and　had　learnt　to　fight　with　their　fists　or　clubs。　Until　this　period　had　arrived　the　antithetical　gesture　of　shrugging　the　shoulders；　as　a　sign　of　impotence　or　of　patience；　would　not　have　been　developed。　　From　the　same　reason　astonishment　would　not　then　have　been　expressed　by　raising　the　arms　with　open　hands　and　extended　fingers。　　Nor；　judging　from　the　actions　of　monkeys；　would　astonishment　have　been　exhibited　by　a　widely　opened　mouth；　but　the　eyes　would　have　been　opened　and　the　eyebrows　arched。　Disgust　would　have　been　shown　at　a　very　early　period　by　movements　round　the　mouth；　like　those　of　vomiting；that　is；　if　the　view　which　I　have　suggested　respecting　the　source　of　the　expression　is　correct；　namely；　that　our　progenitors　had　the　power；　and　used　it；　of　voluntarily　and　quickly　rejecting　any　food　from　their　stomachs　which　they　disliked。　But　the　more　refined　manner　of　showing　contempt　or　disdain；　by　lowering　the　eyelids；　or　turning　away　the　eyes　and　face；　as　if　the　despised　person　were　not　worth　looking　at；　would　not　probably