Observations on lettuce

I have been looking at germinating seeds for nearly a month and have become quite intimate with these 10000 seedlings.  It takes about two hours everyday to go through all of them.  Such devotion leads to observations.

Lettuce seeds are tiny and their seedlings are tiny too.  So small that I couldn't get a very good picture of a newly emerged seedling.  Their two cotyledons are held together when they first emerge and slowly open like butterfly wings.

Soon after sprouting these seedlings turn dark reddish because they are a red variety of romaine lettuce. It can make them a bit hard to spot when counting.

The seedlings in under the opaque white plastic and the clear plastic don't change color.  They remain a lovely green with a bit of red mottling.