that does work if you can only take one thing half-way, but if u cant, here is a solution:
1. Take the chicken to the other side
2. Go back, take the corn to the other side, but as you leave the corn, take the chicken back
3. But as you leave the Chicken there, take the fox accross
4. Go back, take the chicken, and you are done
I also agree that a doctor is the only profession there that requires an I.D. and that he would have the I.D. on him, if they were to all have been women and that the doctor was the only male is mere chance, and has no support if the situation were to be real, but it is true that you don't often see an engineer, lawyer, or judge with a name tag... (maybe an exception is the engineer, who might need some kind of identification at their work place)