▁lay ▁the ▁foundation ▁for ▁v asc ular ▁surg ery , ▁organ ▁trans pl ants , ▁and ▁open - heart ▁surg ery . ▁The ▁develop ments ▁also ▁allowed ▁Gordon ▁Murray ▁to ▁pione er ▁the ▁artificial ▁kid ney ▁in ▁North ▁America . ▁ ▁World ▁War ▁II : ▁ 1 9 3 9 - 1 9 4 5 ▁▁ ▁Canada ▁entered ▁World ▁War ▁II ▁on ▁September ▁ 1 0 , ▁ 1 9 3 9 . ▁In ▁ 1 9 4 0 , ▁Con n aught ▁lost ▁its ▁founder ▁and ▁director ▁Dr . ▁John ▁G . ▁Fitz G er ald ▁to ▁mental ▁health ▁strugg les . ▁Robert ▁Def ries , ▁who ▁had ▁already ▁been ▁leading ▁much ▁of ▁the ▁L abs ' ▁efforts ▁through ▁the ▁ 1 9 3 0 s , ▁stepped ▁in ▁to ▁fill ▁the ▁role ▁as ▁director ▁of ▁Con n aught ▁Labor ator ies ▁and ▁of ▁the ▁School ▁of ▁H yg iene . ▁ ▁This ▁period ▁saw ▁the ▁rapid ▁expansion ▁of ▁Con n aught ' s ▁research ▁capac ities ▁to ▁accommod ate ▁the ▁military ▁dem ands ▁of ▁protection ▁against ▁t et anus , ▁ty ph us , ▁and ▁other ▁b acter ial ▁in fe ctions . ▁The ▁L abs ▁began ▁the ▁war ▁with ▁a ▁staff ▁of ▁ 2 5 2 ; ▁pe aked ▁at ▁ 1 , 5 0 0 ▁staff ▁in ▁ 1 9 4 4 ; ▁and ▁ended ▁the ▁war ▁with ▁a ▁staff ▁of ▁ 8 0 0 . ▁The ▁period ▁also ▁saw ▁heavy ▁collaboration ▁with ▁other ▁local ▁research ers ▁at ▁B