The opposite side the seed is attached to any tree is the side that splits open to send out (a) radicle during germination.
Here you see the Shellbark hickory cultivar Henry splitting open and ready to grow. Another thing about seeds is which way to plant, well, the answer is to plant the seed how it would lay naturally on the ground after falling.
You might consider:
keeping your seeds in a handy cooler with ice water to carry easily and keeping seeds from over heating. It’s really convenient. Grafts you carry around in buckets of ice-alone which are bareroot to plant quickly within the field.
One more tid-bit, Should you prune your hardwoods between the Vernal Equinox, you automatically open them to vectors, pests, insect/disease. It’s impractical for most anyone, however, all pruning should be completed after Sept. 21st and before March 21st.