cause　of　danger。
  _Ruminants_。Cattle　and　sheep　are　remarkable　from　displaying　in　so　slight　a　degree　their　emotions　or　sensations；　excepting　that　of　extreme　pain。　A　bull　when　enraged　exhibits　his　rage　only　by　the　manner　in　which　be　holds　his　lowered　head；　with　distended　nostrils；　and　by　bellowing。　He　also　often　paws　the　ground；　but　this　pawing　seems　quite　different　from　that　of　an　impatient　horse；　for　when　the　soil　is　loose；　he　throws　up　clouds　of　dust。　　I　believe　that　bulls　act　in　this　manner　when　irritated　by　flies；　for　the　sake　of　driving　them　away。　　The　wilder　breeds　of　sheep　and　the　chamois　when　startled　stamp　on　the　ground；　and　whistle　through　their　noses；　and　this　serves　as　a　danger…signal　to　their　comrades。　The　musk…ox　of　the　Arctic　regions；　when　encountered；　likewise　stamps　on　the　ground。＇9＇　How　this　stamping　action　arose　I　cannot　conjecture；　for　from　inquiries　which　I　have　made　it　does　not　appear　that　any　of　these　animals　fight　with　their　fore…legs。
  Some　species　of　deer；　when　savage；　display　far　more　expression　than　do　cattle；　sheep；　or　goats；　for；　as　has　already　been　stated；　they　draw　back　their　ears；　grind　their　teeth；　erect　their　hair；　squeal；　stamp　on　the　ground；　and　brandish　their　horns。　One　day　in　the　Zoological　Gardens；　the　Formosan　deer　（_Cervus　pseudaxis_）　approached　me　in　a　curious　attitude；　with　his　muzzle　raised　high　up；　so　that　the　horns　were　pressed　back　on　his　neck；　the　head　being　held　rather　obliquely。　From　the　expression　of　his　eye　I　felt　sure　that　he　was　savage；　he　approached　slowly；　and　as　soon　as　he　came　close　to　the　iron　bars；　he　did　not　lower　his　head　to　butt　at　me；　but　suddenly　bent　it　inwards；　and　struck　his　horns　with　great　force　against　the　railings。　Mr。　Bartlett　informs　me　that　some　other　species　of　deer　place　themselves　in　the　same　attitude　when　enraged。
  _Monkeys_。The　various　species　and　genera　of　monkeys　express　their　feelings　in　many　different　ways；　and　this　fact　is　interesting；　as　in　some　degree　bearing　on　the　question；　whether　the　so…called　races　of　man　should　be　ranked　as　distinct　species　or　varieties；　for；　as　we　shall　see　in　the　following　chapters；　the　different　races　of　man　express　their　emotions　and　sensations　with　remarkable　uniformity　throughout　the　world。　　Some　of　the　expressive　actions　of　monkeys　are　interesting　in　another　way；　namely　from　being　closely　analogous　to　those　of　man。　As　I　have　had　no　opportunity　of　observing　any　one　species　of　the　group　under　all　circumstances；　my　miscellaneous　remarks　will　be　best　arranged　under　different　states　of　the　mind。
  ＇9＇　‘Land　and　Water；'　1869；　p。　　152。
  _Pleasure；　joy；　affection_It　is　not　possible　to　distinguish　in　monkeys；　at　least　without　more　experience　than　I　have　had；　the　expression　of　pleasure　or　joy　from　that　of　affection。　Young　chimpanzees　make　a　kind　of　barking　noise；　when　pleased　by　the　return　of　any　one　to　whom　they　are　attached。　When　this　noise；　which　the　keepers　call　a　laugh；　is　uttered；　the　lips　are　protruded；　but　so　they　are　under　various　other　emotions。　Nevertheless　I　could　perceive　that　when　they　were　pleased　the　form　of　the　lips　differed　a　little　from　that　assumed　when　they　were　angered。　　If　a　young　chimpanzee　be　tickled　and　the　armpits　are　particularly　sensitive　to　tickling；　as　in　the　case　of　our　children；a　more　decided　chuckling　or　laughing　sound　is　uttered；　though　the　laughter　is　sometimes　noiseless。　The　corners　of　the　mouth　are　then　drawn　backwards；　and　this　sometimes　causes　the　lower　eyelids　to　be　slightly　wrinkled。　But　this　wrinkling；　which　is　so　characteristic　of　our　own　laughter；　is　more　plainly　seen　in　some　other　monkeys。　　The　teeth　in　the　upper　jaw　in　the　chimpanzee　are　not　exposed　when　they　utter　their　laughing　noise；　in　which　respect　they　differ　from　us。　But　their　eyes　sparkle　and　grow　brighter；　as　Mr。　W。　L。　Martin；＇10＇　who　has　particularly　attended　to　their　expression；　states。
  ＇10＇　‘Natural　History　of　Mammalia；'　1841；　vol。　　1。　　pp。　　383；　410。
  Young　Orangs；　when　tickled；　likewise　grin　and　make　a　chuckling　sound；　and　Mr。　Martin　says　that　their　eyes　grow　brighter。　　As　soon　as　their　laughter　ceases；　an　expression　may　be　detected　passing　over　their　faces；　which；　as　Mr。　Wallace　remarked　to　me；　may　be　called　a　smile。　I　have　also　noticed　something　of　the　same　kind　with　the　chimpanzee。　Dr。　Duchenneand　I　cannot　quote　a　better　authorityinforms　me　that　he　kept　a　very　tame　monkey　in　his　house　for　a　year；　and　when　he　gave　it　during　meal…times　some　choice　delicacy；　he　observed　that　the　corners　of　its　mouth　were　slightly　raised；　thus　an　expression　of　satisfaction；　partaking　of　the　nature　of　an　incipient　smile；　and　resembling　that　often　seen　on　the　face　of　main；　could　be　plainly　perceived　in　this　animal。
  The　_Cebus　azarae_；＇11＇　when　rejoiced　at　again　seeing　a　beloved　person；　utters　a　peculiar　tittering　（_kichernden_）　sound。　　It　also　expresses　agreeable　sensations；　by　drawing　back　the　corners　of　its　mouth；　without　producing　any　sound。　　Rengger　calls　this　movement　laughter；　but　it　would　be　more　appropriately　called　a　smile。　　The　form　of　the　mouth　is　different　when　either　pain　or　terror　is　expressed；　and　high　shrieks　are　uttered。　　Another　species　of　_Cebus_　in　the　Zoological　Gardens　（_C。　hypoleucus_）　when　pleased；　makes　a　reiterated　shrill　note；　and　likewise　draws　back　the　corners　of　its　mouth；　apparently　through　the　contraction　of　the　same　muscles　as　with　us。　So　does　the　Barbary　ape　（_Inuus　ecaudatus_）　to　an　extraordinary　degree；　and　I　observed　in　this　monkey　that　the　skin　of　the　lower　eyelids　then　became　much　wrinkled。　　At　the　same　time　it　rapidly　moved　its　lower　jaw　or　lips　in　a　spasmodic　manner；　the　teeth　being　exposed；　but　the　noise　produced　was　hardly　more　distinct　than　that　which　we　sometimes　call　silent　laughter。　　Two　of　the　keepers　affirmed　that　this　slight　sound　was　the　animal's　laughter；　and　when　I　expressed　some　doubt　on　this　head　（being　at　the　time　quite　inexperienced）；　they　made　it　attack　or　rather　threaten　a　hated　Entellus　monkey；　living　in　the　same　compartment。　Instantly　the　whole　expression　of　the　face　of　the　Inuus　changed；　the　mouth　was　opened　much　more　widely；　the　canine　teeth　were　more　fully　exposed；　and　a　hoarse　barking　noise　was　uttered。
  ＇11＇　Rengger　（‘Sagetheire　von　Paraquay'；　1830；　s。　　46）　kept　these　monkeys　in　confinement　for　seven　years　in　their　native　country　of　Paraguay。
  The　Anubis　baboon　（_Cynocephalus　anubis_）　was　first　insulted　and　put　into　a　furious　rage；　as　was　easily　done；　by　his　keeper；　who　then　made　friends　with　him　and　shook　hands。　　As　the　reconciliation　was　effected　the　baboon　rapidly　moved　up　and　down　his　jaws　and　lips；　and　looked　pleased。　　When　we　laugh　heartily；　a　similar　movement；　or　quiver；　may　be　observed　more　or　less　distinctly　in　our　jaws；　but　with　man　the　muscles　of　the　chest　are　more　particularly　acted　on；　whilst　with　this　baboon；　and　with　some　other　monkeys；　it　is　the　muscles　of　the　jaws　and　lips　which　are　spasmodically　affected。
  I　have　already　had　occasion　to　remark　on　the　curious　manner　in　which　two　or　three　species　of　Alacacus　and　the　_Cynopithecus　niger_　draw　back　their　ears　and　utter　a　slight　jabbering　noise；　when　they　are　pleased　by　being　caressed。　　With　the　Cynopithecus　（fig。　17）；　the　corners　of　the　mouth　are　at　the　same　time　drawn　backwards　and　upwards；　so　that　the　teeth　are　exposed。　Hence　this　expression　would　never　be　recognized　by　a　stranger　as　one　of　pleasure。　　The　crest　of　long　hairs　on　the　forehead　is　depressed；　and　apparently　the　whole　skin　of　the　head　drawn　backwards。　The　eyebrows　are　thus　raised　a　little；　and　the　eyes　assume　a　staring　appearance。　　The　lower　eyelids　also　become　slightly　wrinkled；　but　this　wrinkling　is　not　conspicuous；　owing　to　the　permanent　transverse　furrows　on　the　face。
  _Painful　emotions　and　sensations_。With　monkeys　the　expression　of　slight　pain；　or　of　any　painful　emotion；　such　as　grief；　vexation；　jealousy；　&c。；　is　not　easily　distinguished　from　that　of　moderate　anger；　and　these　states　of　mind　readily　and　quickly　pass　into　each　other。　Grief；　however；　with　some　species　is　certainly　exhibited　by　weeping。　A　woman；　who　sold　a　monkey　to　the　Zoological　Society；　believed　to　have　come　from　Borneo　（_Macacus　maurus_　or　_M。　　inornatus_　of　Gray）；　said　that　it　often　cried；　and　Mr。　Bartlett；　as　well　as　the　keeper　Mr。　Sutton；　have　repeatedly　seen　it；　when　grieved；　or　even　when　much　pitied；　weeping　so　copiously　that　the　tears　rolled　down　its　cheeks。　There　is；　however；　something　strange　about　this　case；　for　two　specimens　subsequently　kept　in　the　Gardens；　and　believed　to　be　the　same　species；　have　never　been　seen　to　weep；　though　they　were　carefully　observed　by　the　keeper　and　myself　when　much　distressed　and　loudly　screaming。　Rengger　states＇12＇　that　the　eyes　of　the　_Cebus　azarae_　fill　with　tears；　but　not　sufficiently　to　overflow；　when　it　is　prevented　getting　some　much　desired　object；　or　is　much　frightened。　Humboldt　also　asserts　that　the　eyes　of　the　_Callithrix　sciureus_　〃instantly　fill　with　tears　when　it　is　seized　with　fear；〃　but　when　this　pretty　little　monkey　in　the　Zoological　Gardens　was　teased；　so　as　to　cry　out　loudly；　this　did　not　occur。　I　do　not；　however；　wish　to　throw　the　least　doubt　on　the　accuracy　of　Humboldt's　statement。
  The　appearance　of　dejection　in　young　orangs　and　chimpanzees；　when　out　of　health；　is　as　plain　and　almost　as　pa