Help stems are coming out the dirt black?????

I planted about three seeds in each of 10 different cups and two have spouted. But the two that spouted came out black and almost look like a root but theres just a single one in both cups??? Any ideas of what this is?
Any and all help appreciated!

let them be and let them do what they want just make sure its warm and a nice humidity level, no nutes yet.

ok and also one is growing straight up toward the light ( seems to look a lil better) and the other is literally growing along the top of the dirt near the rim of the cup its about and 2 inchs long now

Ok so its been a couple days and the two stems arr still extremely black but growing and two more have sprouted just as green as grass and look like they are on the right track. So should i even keep the black ones or should i give all my attention and light to the newbies??