Itistimethatwethoughtofexperimenting。TheMason-beesintendedforthejourneymustbemarkedwithasignwherebyImayknowthem。A
solutionofgumarabic，thickenedwithacolouring-powder，red，blueorsomeothershade，isthematerialwhichIusetomarkmytravellers。Thevarietyinhuewillsavemefromconfusingthesubjectsofmydifferentexperiments。
Whenmakingmyformerinvestigations，IusedtomarktheBeesattheplacewhereIsetthemfree。Forthisoperation，theinsectshadtobeheldinthefingersoneaftertheother；andIwasthusexposedtofrequentstings，whichsmartedallthemoreforbeingconstantlyrepeated。TheconsequencewasthatIwasnotalwaysquiteabletocontrolmyfingersandthumbs，tothegreatdetrimentofmytravellers；forIcouldeasilywarptheirwing-jointsandthusweakentheirflight。Itwasworthwhileimprovingthemethodofoperation，bothinmyowninterestandinthatoftheinsect。ImustmarktheBee，carryhertoadistanceandreleaseher，withouttakingherinmyfingers，withoutoncetouchingher。Theexperimentwasboundtogainbytheseniceprecautions。IwilldescribethemethodwhichIadopted。
TheBeeissomuchengrossedinherworkwhensheburiesherabdomeninthecellandridsherselfofherloadofpollen，orwhensheisbuilding，thatitiseasy，atsuchtimes，withoutalarmingher，tomarktheuppersideofthethoraxwithastrawdippedinthecolouredglue。Theinsectisnotdisturbedbythatslighttouch。Itfliesoff；
itreturnsladenwithmortarorpollen。Youallowthesetripstoberepeateduntilthemarkonthethoraxisquitedry，whichsoonhappensinthehotsunnecessarytotheBee’slabours。Thenextthingistocatchherandimprisonherinapaperbag，stillwithouttouchingher。