"Autopsy Class" joke

An
autopsy professor was giving an introductory lecture
to a class of students. Standing over a corpse, he addressed
the class. 'There are two things you need to make a
career in medical forensics. First, you must have no
fear.' Having said that, he shoved his finger up the
corpse's anus and licked it. 'Now you must do the same,'
he told the class.
After a couple of minutes of uneasy silence, the
class did as instructed.
'Second,' the professor continued, 'you must have
an acute sense of observation. For instance, how many
of you noticed that I put my middle finger up this
man's anus, but licked my index finger?'