I imprinted hard on McDowall's ape characters (those movies had only just finished coming out when I was a kid, and I watched the short-lived TV show when it aired), but I think McDowall also guest-starred on a ton of late '60s/early '70s TV shows I happened to see. Shows like Love American Style--I remember nothing about his appearance, just that he was on the show and I saw it many years ago!