dagger frogs???

[bahnschutz1]

does anybody know why a dagger or bayo frog is called a frog? had several non collectors ask me this and I have to admit I don't know the answer . I tried to research and can't seem to come up with anything that seems to add up. when was the term first used?
thanks ahead
jim

[SCHUPO]

I think that frogs have been called that for a long time. I do recall reading in US Civil War period manuals and catalogs that they were called both a frog and a throg. I guess the better question might be why call it a throg?