▁on ▁the ▁coast ▁of ▁Wales ▁to ▁rev ise ▁their ▁studies ▁with ▁private ▁tut ors . ▁For ▁Charles ▁it ▁was ▁an ▁" Ent omo - Math emat ical ▁expedition ". ▁Though ▁he ▁badly ▁needed ▁to ▁catch ▁up ▁with ▁his ▁mathematics , ▁the ▁insect ▁collect ing ▁pre domin ated ▁along ▁with ▁pleasant ▁divers ions ▁such ▁as ▁hill walk ing , ▁bo ating ▁and ▁fly ▁fish ing . ▁He ▁went ▁on ▁daily ▁wal ks ▁with ▁his ▁close ▁friend , ▁the ▁older ▁student ▁John ▁Maurice ▁Herbert ▁who ▁he ▁dub bed ▁" Ch er bury " ▁after ▁Herbert ▁of ▁Cher bury , ▁the ▁father ▁of ▁English ▁De ism . ▁Herbert ▁assist ed ▁with ▁the ▁insect ▁collect ing , ▁but ▁the ▁usual ▁outcome ▁was ▁that ▁Dar win ▁would ▁examine ▁Herbert ' s ▁collect ing ▁bott le ▁and ▁say ▁" Well , ▁old ▁Cher bury , ▁none ▁of ▁these ▁will ▁do ." ▁In ▁September ▁Dar win ▁wrote ▁to ▁tell ▁" My ▁dear ▁old ▁Cher bury " ▁that ▁his ▁own ▁catch es ▁had ▁included ▁" some ▁of ▁the ▁r ar est ▁of ▁the ▁British ▁In sect s , ▁& ▁their ▁being ▁found ▁near ▁Bar mouth ▁is ▁quite ▁unknown ▁to ▁the ▁Ent om ological ▁world : ▁I ▁think ▁I ▁shall ▁write ▁& ▁inform ▁some ▁of ▁the ▁crack ▁Ent om olog ists ." ▁He ▁described ▁these ▁" ext rem ely ▁rare " ▁insect s ▁and ▁asked ▁Herbert ▁to ▁ob lige ▁him ▁by ▁collect ing ▁some ▁more ▁of ▁them . ▁ ▁Second ▁year ▁d old rum s ▁ ▁At ▁the ▁start ▁of ▁his ▁second