t of Congress, * * *, to keep the channels of interstate
commerce free from the carriage of injurious or fraudulently branded
articles and to choose appropriate means to that end."[993] But a North
Dakota statute requiring that lard compound or substitutes, unless sold
in bulk, should be put up in pails or containers holding one, three, or
five pounds net weight, or some multiple of these numbers, was held not
to be repugnant to the Pure Food and Drugs Act.[994] On the other hand,
a decade later the Court found that the Plant Quarantine Act of 1912, as
amended in 1917,[995] had so completely occupied the field indicated by
its title that a State was left without power to prevent the importation
of plants infected by a particular disease to which the Secretary of
Agriculture's regulations did not apply.[996] Congress promptly
intervened by further amending the federal statute to permit the States
to impose quarantines in such overlooked cases.[997]

RECENT CASES SUSTAINING STATE LEGISLATION

In 1935, it was held[998] that an order of the New York Commissioner of
Agriculture prohibiting the importation of cattle for dairy or breeding
purposes unless such cattle and the herds from which they come had been
certified by the chief sanitary officer of the State of origin as being
free from Bang's disease, was not in conflict with the Cattle Contagious
Diseases Acts.[999] In 1937, it was ruled[1000] that a Georgia statute
fixing maximum charges for handling and selling leaf tobacco did not, as
applied to sales of tobacco destined for export, conflict with the
Tobacco Inspection Act.[1001] In 1942,[1002] it was held that an order
of the Wisconsin Employment Relations Board which commanded a union, its
agents, and members, to desist from mass picketing of a factory,
threatening personal injury or property damage to employees desiring to
work, obstructing the streets about the factory, and picketing the homes
of employees, was not in conflict with the National Labor Relations
Act,[1003] to which the employer was admittedly subject but which had
not been invoked. An "intention of Congress," said the Court, "to
exclude States from exerting their police power must be clearly
manifested."[1004] In 1943,[1005] the Court sustained the marketing
program for the 1940 California raisin crop, adopted pursuant to the
California Agricultural Prorate Act. Although it was conceded that the
program and act operated to eliminate competition amo