Much attention has been given during the 20th century to the 10-year cycle in the population of forest fur-bearing animals in Canada and its effect upon the fur trade and wild life generally. This paper investigates the relationship between the quantity of furs sold at the annual London auctions and the prices achieved at the auctions. Using bivariate time-series techniques equations relating price and supply are estimated and are then employed to answer the following questions: 1. (1) Are there cycles in prices due to fashion, business conditions or any other factors, which might have caused the cycles in quantities? 2. (2) Are supplies sold in one period influenced by prices obtained in previous periods? It is found that for most animals, and in particular for lynx and muskarts, there is no statistical evidence that the cycles in supply have been induced by cycles in prices.