Hi Leslie, thanks for writing in. A sheaf or bundle of wheat on a Elgin hunter-case pocket watch is the makers mark for the Brooklyn Watch Case Company . This mark is no longer in active. It was current from 1865 - 1920, This makers mark guarantees the case will test positive for solid gold although it is actually "layered" or "plated" gold.
Regards Yvonne The Vaulted Shelf www.thevaultedshelf.com