Lyrics to THE WHISTLER'S MOTHER-IN-LAW have been posted in the thread called Folk songs for anglers. I have one correction to those lyrics, which I got from listening to sound samples:

A whistle for all your plans now for the good they'll do.

And I have the following information:

THE WHISTLER'S MOTHER-IN-LAW
(Bert Stevens / Larry Wagner)
As sung by Bing Crosby & Muriel Lane with Woody Herman's Woodchoppers, 1941.

[Also recorded by Orrin Tucker and His Orchestra, The Milt Herth Trio, Shep Fields & His New Music, and Skinnay Ennis & His Orchestra, all in 1941.]