The ins and outs of spermatology

Cause ya see, these fellas are built for function And sacrifice is their middle name. But they'll do all they can just to survive Just like a guy for some dame. They don't have legs for travelin' But you'll n' er hear them complain, For during their hike to the Promised Land You ever see a sperm go lame? But these cute little guys are a little mixed up And they really take this to heart, For some are Xs and some are Ys And they can't tell each other apart. Now these swordless soldiers must fight to the death Cause out of the billions one wins, And it sounds like something from out of the Ozarks Cause they only compete with their kin. So sit back pardners, and listen close About these unique creatures we try to decode We'll follow their journey, discuss their ins and their outs As they travel the Yellow Brick Road. Now Webster himself defines Ins and Outs As discussions with a technical slant, So when you see a title like this Get curious rather than rant. You see, sperm have a likeness like no other A fact for which we must all agree, So a title addressed in a manner like this Fits my talk to a tee. From their diminutive size to their wigglin' ways They have uniqueness beyond compare. To start, just think of them as skinny little guys That don't have to worry about skin care. Yep, they have their idiosyncrasies, indeed Like no brain and no heart, but endurance, And the Wizard of Oz would be proud to know That these fellas are loaded with courage. For they must travel great long distances indeed And it begins at the time they are born. There are billions of sperm that start this long trek And most don't make it, but don't mourn.