Simplify the following text for a Grade 12 native English-speaking person.
Original: In 1967 he was admitted into the Royal College of Pathologists of Australia and became a senior pathologist at the Royal Perth Hospital where he spent the majority of his career .
Simplified: In 1967 he was became a member the Royal College of Pathologists of Australia and became a senior pathologist at the Royal Perth Hospital where he spent most of his career .