What is the scope of federal trade and commerce powers in s. 91(2)?

The jurisprudence on the general trade and commerce power reflects this fundamental principle. An overly expansive interpretation of the federal trade and commerce power under s. 91(2) not only would subsume many more specific federal heads of power (e.g., federal power over banking (s. 91(15)), weights and measures (s. 91(17)), bills of exchange and promissory notes (s. 91(18))), but, more importantly, would have the potential to duplicate and perhaps displace, through the paramountcy doctrine, the clear provincial powers over local matters and property and civil rights which embrace trade and commerce in the province. Duff J. (as he then was) expressed this concern in the following manner in Lawson v. Interior Tree Fruit and Vegetable Committee of Direction, 1930 CanLII 91 (SCC), [1931] S.C.R. 357: The scope which might be ascribed to head 2, s. 91 (if the natural meaning of the words, divorced from their context, were alone to be considered), has necessarily been limited, in order to preserve from serious curtailment, if not from virtual extinction, the degree of autonomy which . . . the provinces were intended to possess. [p. 366]