Watching seeds germinate

Hi,

I have been watching some small seeds germinate on different media.

The root pops out first, from a split in one end of the seed, navigates down to the substrate, then inserts itself into the substrate if it can (e.g. when placed on sand or soil). Otherwise it grows along the surface horizontally (on filter paper). The vertical growing plant also puts out a horizontal set of very fine root hairs, at the ground surface, and then stands up, lifting the seed into the air with the first leaves still stuck inside the seed.

My question here is, does the plant lever itself up against the radiating mat of lateral hairs, or does it lever against the root in the ground, or both?

I guess I should be taking time-lapse movies of all this. All of these mechanical efforts by the plant are aimed at getting up to the light, fast, before other competing plants do - but then how do explain what I see when a clump of seeds germinate all together, seemingly as one mass?

That's another story, maybe.