Thecrabbeginsbytearingthehusk，fibrebyfibre，andalwaysfromthatendunderwhichthethreeeye-holesaresituated；whenthisiscompleted，thecrabcommenceshammeringwithitsheavyclawsononeoftheeye-holestillanopeningismade。Thenturningrounditsbody，bytheaidofitsposteriorandnarrowpairofpincers，itextractsthewhitealbuminoussubstance。IthinkthisisascuriousacaseofinstinctaseverIheardof，andlikewiseofadaptationinstructurebetweentwoobjectsapparentlysoremotefromeachotherintheschemeofnature，asacrabandacocoa-nuttree。TheBirgosisdiurnalinitshabits；buteverynightitissaidtopayavisittothesea，nodoubtforthepurposeofmoisteningitsbranchiae。
Theyoungarelikewisehatched，andliveforsometime，onthecoast。Thesecrabsinhabitdeepburrows，whichtheyhollowoutbeneaththerootsoftrees；andwheretheyaccumulatesurprisingquantitiesofthepickedfibresofthecocoa-nuthusk，onwhichtheyrestasonabed。TheMalayssometimestakeadvantageofthis，andcollectthefibrousmasstouseasjunk。Thesecrabsareverygoodtoeat；moreover，underthetailofthelargeronesthereisamassoffat，which，whenmelted，sometimesyieldsasmuchasaquartbottlefulloflimpidoil。IthasbeenstatedbysomeauthorsthattheBirgoscrawlsupthecocoa-nuttreesforthepurposeofstealingthenuts：Iverymuchdoubtthepossibilityofthis；butwiththePandanus[8]thetaskwouldbeverymucheasier。IwastoldbyMr。LieskthatontheseislandstheBirgoslivesonlyonthenutswhichhavefallentotheground。
CaptainMoresbyinformsmethatthiscrabinhabitstheChagosandSeychellegroups，butnottheneighbouringMaldivaarchipelago。ItformerlyaboundedatMauritius，butonlyafewsmallonesarenowfoundthere。InthePacific，thisspecies，oronewithcloselyalliedhabits，issaid[9]toinhabitasinglecoralisland，northoftheSocietygroup。Toshowthewonderfulstrengthofthefrontpairofpincers，Imaymention，thatCaptainMoresbyconfinedoneinastrongtin-box，whichhadheldbiscuits，thelidbeingsecuredwithwire；butthecrabturneddowntheedgesandescaped。
Inturningdowntheedges，itactuallypunchedmanysmallholesquitethroughthetin！
IwasagooddealsurprisedbyfindingtwospeciesofcoralofthegenusMilleporaM。complanataandalcicornis，possessedofthepowerofstinging。