of　the　orbicular　muscles　may　serve　in　addition　to　protect　the　eyes　from　too　severe　a　jar　or　vibration。　I　think　so；　because　dogs　and　cats；　in　crunching　hard　bones；　always　close　their　eyelids；　and　at　least　sometimes　in　sneezing；　though　dogs　do　not　do　so　whilst　barking　loudly。　　Mr。　Sutton　carefully　observed　for　me　a　young　orang　and　chimpanzee；　and　he　found　that　both　always　closed　their　eyes　in　sneezing　and　coughing；　but　not　whilst　screaming　violently。　I　gave　a　small　pinch　of　snuff　to　a　monkey　of　the　American　division；　namely；　a　Cebus；　and　it　closed　its　eyelids　whilst　sneezing；　but　not　on　a　subsequent　occasion　whilst　uttering　loud　cries。
  _Cause　of　the　secretion　of　tears_。It　is　an　important　fact　which　must　be　considered　in　any　theory　of　the　secretion　of　tears　from　the　mind　being　affected；　that　whenever　the　muscles　round　the　eyes　are　strongly　and　involuntarily　contracted　in　order　to　compress　the　blood…vessels　and　thus　to　protect　the　eyes；　tears　are　secreted；　often　in　sufficient　abundance　to　roll　down　the　cheeks。　This　occurs　under　the　most　opposite　emotions；　and　under　no　emotion　at　all。　　The　sole　exception；　and　this　is　only　a　partial　one；　to　the　existence　of　a　relation　between　the　involuntary　and　strong　contraction　of　these　muscles　and　the　secretion　of　tears　is　that　of　young　infants；　who；　whilst　screaming　violently　with　their　eyelids　firmly　closed；　do　not　commonly　weep　until　they　have　attained　the　age　of　from　two　to　three　or　four　months。　Their　eyes；　however；　become　suffused　with　tears　at　a　much　earlier　age。　It　would　appear；　as　already　remarked；　that　the　lacrymal　glands　do　not；　from　the　want　of　practice　or　some　other　cause；　come　to　full　functional　activity　at　a　very　early　period　of　life。　With　children　at　a　somewhat　later　age；　crying　out　or　wailing　from　any　distress　is　so　regularly　accompanied　by　the　shedding　of　tears；　that　weeping　and　crying　are　synonymous　terms。＇18＇
  Under　the　opposite　emotion　of　great　joy　or　amusement；　as　long　as　laughter　is　moderate　there　is　hardly　any　contraction　of　the　muscles　round　the　eyes；　so　that　there　is　no　frowning；　but　when　peals　of　loud　laughter　are　uttered；　with　rapid　and　violent　spasmodic　expirations；　tears　stream　down　the　face。　I　have　more　than　once　noticed　the　face　of　a　person；　after　a　paroxysm　of　violent　laughter；　and　I　could　see　that　the　orbicular　muscles　and　those　running　to　the　upper　lip　were　still　partially　contracted；　which　together　with　the　tear…stained　cheeks　gave　to　the　upper　half　of　the　face　an　expression　not　to　be　distinguished　from　that　of　a　child　still　blubbering　from　grief。　The　fact　of　tears　streaming　down　the　face　during　violent　laughter　is　common　to　all　the　races　of　mankind；　as　we　shall　see　in　a　future　chapter。
  In　violent　coughing　especially　when　a　person　is　half…choked；　the　face　becomes　purple；　the　veins　distended；　the　orbicular　muscles　strongly　contracted；　and　tears　run　down　the　cheeks。　　Even　after　a　fit　of　ordinary　coughing；　almost　every　one　has　to　wipe　his　eyes。　In　violent　vomiting　or　retching；　as　I　have　myself　experienced　and　seen　in　others；　the　orbicular　muscles　are　strongly　contracted；　and　tears　sometimes　flow　freely　down　the　cheeks。　　It　has　been　suggested　to　me　that　this　may　be　due　to　irritating　matter　being　injected　into　the　nostrils；　and　causing　by　reflex　action　the　secretion　of　tears。　Accordingly　I　asked　one　of　my　informants；　a　surgeon；　to　attend　to　the　effects　of　retching　when　nothing　was　thrown　up　from　the　stomach；　and；　by　an　odd　coincidence；　he　himself　suffered　the　next　morning　from　an　attack　of　retching；　and　three　days　subsequently　observed　a　lady　under　a　similar　attack；　and　he　is　certain　that　in　neither　case　an　atom　of　matter　was　ejected　from　the　stomach；　yet　the　orbicular　muscles　were　strongly　contracted；　and　tears　freely　secreted。　I　can　also　speak　positively　to　the　energetic　contraction　of　these　same　muscles　round　the　eyes；　and　to　the　coincident　free　secretion　of　tears；　when　the　abdominal　muscles　act　with　unusual　force　in　a　downward　direction　on　the　intestinal　canal。
  ＇18＇　Mr。　Hensleigh　Wedgwood　（Dict。　of　English　Etymology；　1859；　vol。　　i。　　p。　　410）　says；　〃the　verb　to　weep　comes　from　Anglo…Saxon　_wop_；　the　primary　meaning　of　which　is　simply　outcry。〃
  Yawning　commences　with　a　deep　inspiration；　followed　by　a　long　and　forcible　expiration；　and　at　the　same　time　almost　all　the　muscles　of　the　body　are　strongly　contracted；　including　those　round　the　eyes。　During　this　act　tears　are　often　secreted；　and　I　have　seen　them　even　rolling　down　the　cheeks。
  I　have　frequently　observed　that　when　persons　scratch　some　point　which　itches　intolerably；　they　forcibly　close　their　eyelids；　but　they　do　not；　as　I　believe；　first　draw　a　deep　breath　and　then　expel　it　with　force；　and　I　have　never　noticed　that　the　eyes　then　become　filled　with　tears；　but　I　am　not　prepared　to　assert　that　this　does　not　occur。　The　forcible　closure　of　the　eyelids　is；　perhaps；　merely　a　part　of　that　general　action　by　which　almost　all　the　muscles　of　the　body　are　at　the　same　time　rendered　rigid。　　It　is　quite　different　from　the　gentle　closure　of　the　eyes　which　often　accompanies；　as　Gratiolet　remarks；＇19＇　the　smelling　a　delicious　odour；　or　the　tasting　a　delicious　morsel；　and　which　probably　originates　in　the　desire　to　shut　out　any　disturbing　impression　through　the　eyes。
  ＇19＇　‘De　la　Physionomie；'　1865；　p。　　217。
  Professor　Donders　writes　to　me　to　the　following　effect：　〃I　have　observed　some　cases　of　a　very　curious　affection　when；　after　a　slight　rub　（_attouchement_）；　for　example；　from　the　friction　of　a　coat；　which　caused　neither　a　wound　nor　a　contusion；　spasms　of　the　orbicular　muscles　occurred；　with　a　very　profuse　flow　of　tears；　lasting　about　one　hour。　　Subsequently；　sometimes　after　an　interval　of　several　weeks；　violent　spasms　of　the　same　muscles　re…occurred；　accompanied　by　the　secretion　of　tears；　together　with　primary　or　secondary　redness　of　the　eye。〃　Mr。　Bowman　informs　me　that　be　has　occasionally　observed　closely　analogous　cases；　and　that；　in　some　of　these；　there　was　no　redness　or　inflammation　of　the　eyes。
  I　was　anxious　to　ascertain　whether　there　existed　in　any　of　the　lower　animals　a　similar　relation　between　the　contraction　of　the　orbicular　muscles　during　violent　expiration　and　the　secretion　of　tears；　but　there　are　very　few　animals　which　contract　these　muscles　in　a　prolonged　manner；　or　which　shed　tears。　　_The　Macacus　maurus_；　which　formerly　wept　so　copiously　in　the　Zoological　Gardens；　would　have　been　a　fine　case　for　observation；　but　the　two　monkeys　now　there；　and　which　are　believed　to　belong　to　the　same　species；　do　not　weep。　Nevertheless　they　were　carefully　observed　by　Mr。　Bartlett　and　myself；　whilst　screaming　loudly；　and　they　seemed　to　contract　these　muscles；　but　they　moved　about　their　cages　so　rapidly；　that　it　was　difficult　to　observe　with　certainty。　　No　other　monkey；　as　far　as　I　have　been　able　to　ascertain；　contracts　its　orbicular　muscles　whilst　screaming。
  The　Indian　elephant　is　known　sometimes　to　weep。　　Sir　E。　Tennent；　in　describing　these　which　he　saw　captured　and　bound　in　Ceylon；　says；　some　〃lay　motionless　on　the　ground；　with　no　other　indication　of　suffering　than　the　tears　which　suffused　their　eyes　and　flowed　incessantly。〃　Speaking　of　another　elephant　he　says；　〃When　overpowered　and　made　fast；　his　grief　was　most　affecting；　his　violence　sank　to　utter　prostration；　and　he　lay　on　the　ground；　uttering　choking　cries；　with　tears　trickling　down　his　cheeks。〃＇20＇　In　the　Zoological　Gardens　the　keeper　of　the　Indian　elephants　positively　asserts　that　he　has　several　times　seen　tears　rolling　down　the　face　of　the　old　female；　when　distressed　by　the　removal　of　the　young　one。　　Hence　I　was　extremely　anxious　to　ascertain；　as　an　extension　of　the　relation　between　the　contraction　of　the　orbicular　muscles　and　the　shedding　of　tears　in　man；　whether　elephants　when　screaming　or　trumpeting　loudly　contract　these　muscles。　　At　Mr。　Bartlett's　desire　the　keeper　ordered　the　old　and　the　young　elephant　to　trumpet；　and　we　repeatedly　saw　in　both　animals　that；　just　as　the　trumpeting　began；　the　orbicular　muscles；　especially　the　lower　ones；　were　distinctly　contracted。　On　a　subsequent　occasion　the　keeper　made　the　old　elephant　trumpet　much　more　loudly；　and　invariably　both　the　upper　and　lower　orbicular　muscles　were　strongly　contracted；　and　now　in　an　equal　degree。　It　is　a　singular　fact　that　the　African　elephant；　which；　however；　is　so　different　from　the　Indian　species　that　it　is　placed　by　some　naturalists　in　a　distinct　sub…genus；　when　made　on　two　occasions　to　trumpet　loudly；　exhibited　no　trace　of　the　contraction　of　the　orbicular　muscles。
  ＇20＇　‘Ceylon；'　3rd　edit。　　1859；　vol。　　ii。　　pp。　　364；　376。　I　applied　to　Mr。　Thwaites；　in　Ceylon；　for　further　information　with　respect　to　the　weeping　of　the　elephant；　and　in　consequence　received　a　letter　from　the　Rev。　Mr　Glenie；　who；　with　others；　kindly　observed　for　me　a　herd　of　recently　captured　elephants。　These；　when　irritated；　screamed　violently；　but　it　is　remarkable　that　they　never　when　thus　screaming　contracted　the　muscles　round　the　eyes。　Nor　did　they　shed　tears；　and　the　native　hunters　asserted　that　they　had　never　observed　elephants　weeping。　　Nevertheless；　it　appears　to　me　impossible　to　doubt　Sir　E。　Tennent's　distinct　details　about　their　weeping；　supported　as　they　are　by　the　positive　assertion　of　the　keeper　in　the　Zoo