Blue Silk Pajamas

A biologist phones his wife from his office and says:

- Honey, something has just come up, I realize its not my field season, but I have to visit my field site for a week. So, would you pack my clothes, my field equipment and my blue silk pajamas? I'll be home in 1 hour to pick them up.

A week later he returned.

- Did you have a good trip, dear? - his wife asked.

- Oh, it was just a typical field trip, you know, work work work - he exclaimed, and added:

- But you forgot to pack my blue silk pajamas.

- No I didn't - she replied - I put them in the box of field equipment!