>>216
only 1% of sperm would get to the destination, unless penis had a sucking in function somehow. This sucking organ would've been 5 times bigger than male balls, and would've been unactive for the most of human's lifetime, just taking space. Just terribly unefficient all around. You would need a way to clean it of sucked in dust or something like that, this means extra excretions. Plus sperm needs a temperature a bit lower than the rest of the body, this means this female would still need balls and would still need the channel to deliver sperm from balls into the sucking penis. If you go that far, might as well just deliver all the way into the female's body. It is probably possible to have semen production without balls, but resulting semen probably wouldn't be able to move as freely or something, human body probably has its temperature for a reason, to kill as much of alien organisms that try to get inside as possible.