ies
to the permissible area of State legislative activity. There are. And
none is more certain than the prohibition against attempts on the part
of any single State to isolate itself from difficulties common to all of
them by restraining the transportation of persons and property across
its borders. It is frequently the case that a State might gain a
momentary respite from the pressure of events by the simple expedient of
shutting its gates to the outside world. But, in the words of Mr.
Justice Cardozo: 'The Constitution was framed under the dominion of a
political philosophy less parochial in range. It was framed upon the
theory that the peoples of the several States must sink or swim
together, and that in the long run prosperity and salvation are in union
and not division'."[955] Four of the Justices would have preferred to
rest the holding of unconstitutionality on the rights of national
citizenship under the privileges and immunities clause of Amendment
XIV.[956]

STATE CONSERVATION AND EMBARGO MEASURES

In Geer _v._ Connecticut[957] the Court sustained the right of the State
to forbid the shipment beyond its borders of game taken within the
State--this on the ground, in part, that a State has an underlying
property right to wild things found within its limits, and so is
entitled to qualify the right of individual takers thereof to any
extent it chooses; and a similar ruling was laid down in a later case as
to the prohibition by a State of the transportation out of it of water
from its important streams.[958] In Oklahoma _v._ Kansas Natural Gas
Co.,[959] however, this doctrine was held inapplicable to the case of
natural gas, on the ground: first, that "gas, when reduced to
possession, is a commodity, the individual property" of the owner; and
secondly, that "the business welfare of the State," is subordinated by
the commerce clause to that of the nation as a whole. If the States had
the power asserted in the Oklahoma statute, said Justice McKenna, "a
singular situation might result. Pennsylvania might keep its coal, the
Northwest its timber, the mining States their minerals. And why may not
the products of the field be brought within the principle? * * * And yet
we have said that 'in matters of foreign and interstate commerce there
are no State lines.' In such commerce, instead of the States, a new
power appears and a new welfare, a welfare which transcends that of any
State. But rather let us say it is constit