This should help:Attachment 288447Attachment 288448

Well, it would if this board hadn't hosed up my pics.

Crap! now I gotta type.

Basicall, pot seeds are teardrop shaped.
They fall to the ground pointy end up.
The root emerges from the pointy end and is programmed to turn 180 degrees.
It does a u-turn.

That lets it push the root down without pushing the seed out of the ground.
When the root is established, it uses the bent part to drag it's self out of the ground backwards.
Which helps it shed it's husk.

Start with the tap root pointing up, and you seldom have to deal with a stuck-on seed husk.
The seedlings break ground sooner and healthier.

If you plant them with the emerging root pointed down, (which seems logical), they do their u-turn, start to see light, and do another u-turn.
That extra step uses up energy stored in the seed.

Causes stunting, or at the least, wimpyness, as the double bend slows transpiration.

Agrowha,
Weezard