1930's Logging Video

I saw this over on the Railroad Lines Forum this AM. It is great. What a dangerous profession moving those huge logs around.

Could not figure out what the yellow cheesy stuff at the beginning of the movie was. Fungus? Mold? Mushrooms?

Doc Tom:mrgreen:
 
One of my fav youtube vids. The owner of the video said in the comments that it's probably some kind of fungus, that'd be my guess as well.