Some of you that follow my blogs have probably noted that I have an inordinate interest in Canadian Coins, that interest also extends to Currency, Medals, and Ephemera.  I was hoping one of you has the answer to a question I have about the two bills pictured.  They are both from 1967, they both have the Canadian Centennial Maple Leaf logo on the obverse and they both have the Old Parliament Building on the reverse.  But, and its an important but, one has a serial number and one has the dual dates 1867 1967 in place of the serial number.  They are both legal tender and neither is worth much unless in fairly high grades.  So here's the question.  Why the difference?   Is the dual dated example meant to be distributed to collectors only while the serial numbered example is for general circulation?  Was one issued before the other, in other words, did one issue replace the other?   I am doing research for an article I am writing on the general subject of Canada 1967 and I would like to flesh out the article with the straight story on this variation.   PS- the Post Card is just for fun, it shows all the Canadian Provinces at the time of the centennial.   It does not include the Yukon or Northwest Territories.  Since 1967, no new provinces but the eastern half of the Northwest Territory has had the Nunavut Territory calved off its eastern flank like a big iceberg.