Blotchy Photos

In the photo department of a local pharmacy the pictures were sometimes
developed incorrectly. If this occurred, the clerk did not charge the
customer. Once a man came to pick up his pictures, which were marked
$0.00, indicating that not one of them had turned out right.

The customer asked to see the photos, and when the clerk noticed the odd
splotches of color all over the pictures, the clerk apologized
profusely.

"Oh, no, these are fine," the customer said happily. "I'm a
microbiologist, and these are pictures of my bacteria cultures."