http://www.ebay.com/itm/271570365132
This vintage canvas bag was made in the mid 1930s and was used by the US Biological Survey for poisoned grain, which was used to eliminate “undesirable species” from the western states of America to clear the way for agriculture and ranching. The Bureau of Biological Survey was created in 1934 and lasted until 1940, when the Fish and Wildlife Service was created.
The bag is made of selvedge canvas, with the selvedge edge by the zipper. The zipper is a very early Talon, made in the same shape as earlier Hookless zippers. The buckle has anchor and “W” hallmarks.