At Harvey Mudd College, when I was there in the 80s, the Computer Science department was part of the Biology department: They had one prof who did CS exclusively, one who did Biology exclusively, and one who did both. The “real” departments, Mathematics, Physics, Chemistry and Engineering all offered the option to do a CS option within them, but one of the cool things about Mudd of that era (I’m not sure how much of this has survived since then), was that you didn’t really do a specialized degree in Math, Physics, etc. but got a good broad education across the discipline.