Two brothers enlisting in the Army were getting their physicals. 
During the inspection, the doctor was surprised to discover that 
both of them possessed incredibly long, oversized penises. 

"How do you account for this?" he asked the brothers.

"It's hereditary, sir," the older one replied.

"I see," said the doctor, writing in his file. "Your father's the 
reason for your elongated penises?"

"No sir, our mother."

"Your mother? You idiot, women don't have penises!"

"I know, sir," replied the recruit, "but she only had one arm, and 
when it came to getting us out of the bathtub, she had to 
manage as best she could."