Mr. Justice Brewer,
after stating the case, delivered the opinion of the court.
The ordinary rule with respect to lands within indemnity limits is, that no title passes until selection. Where, as here, the deficiency within the granted limits is so great that' all the indemnity lands will not make good the loss, it has been held, in a contest between two railroad companies, that no formal selection was necessary to give them to the one having the older grant, as against the other company. St. Paul & Pacific Railroad v. Northern Pacific Railroad, 139 U. S. 1. And if the Atlantic and Pacific Company had constructed its road, it would be difficult in the light of that decision to avoid the conclusion that all the lands within the indemnity limits passed to that company. But this case does not rest upon that proposition. One thing which distinguishes the grant of 1871 to the Southern Pacific Eailroad Company from most, if not all other, land grants is the proviso somewhat considered in the opinion in the former cases, and which reads: " Provided, however, That this section shall in no way affect or impair the rights, present or prospective, of -the Atlantic and Pacific Railroad Company, or any other railroad company." . .
What is the significance of this proviso % Without it, certainly, the Southern Pacific, its grant being .of later date, would be postponed to the Atlantic and Pacific; and on the filing by each company of a map of definite location, the title to the lands within the granted limits would vest in the Atlantic and Pacific Company, to the total and absolute exclusion of all claims on the part of the Southern Pacific. The proviso, therefore, was without significance, in respect to such lands. It in no manner strengthened the title of the Atlantic and Pacific, and took nothing away from the Southern'Pacific. Yet it cannot be supposed that this proviso was meaningless, and that Congress intended nothing by it. Carefully inserted, in a way to distinguish this grant from ordinary later and conflicting grants, it must be held that Congress meant by it to impose limitations and restrictions different from those generally imposed in such cases, and it in substance declared that the Southern Pacific Company should not in any event take lands to .which any other company had at the time a present or prospective right. As it could have no effect upon the lands within the granted limits, it must have been intended to have some effect upon those within the indemnity limits, they being the only lands upon which it could operate.
What were the prospective rights of the Atlantic and Pacific Company ? Of course it could not be known at the time of the passage of the later act exactly where the lines of. the two companies would be located, and where the point of crossing would be. Neither could it then be known that there would be any deficiency in the granted lands at the point of crossing, or that, if such deficiency existed, it would require all the indemnity lands to make good the loss. It might well be assumed that very likely the Atlantic and Pacific Company would. be called upon to select from. the indemnity lands a portion sufficient to make good the defir ciency, in the granted limits. That right of selection was a prospective right, and if it was to be fully exercised, no adverse title could be created to any lands within the indemnity limits. Suppose, for instance, it should -turn out that -only half of the indemnity lands were necessary to make good the deficiency, and that one-half of such lands were well watered and valuable, while the remainder were arid and comparatively valueless, obviously the right of selection would be seriously impaired if it were limited to only the arid and valueless tracts. In fact, every withdrawal of lands from the aggregate of those from which selection could be made would more or less impair the value of the right of selection. The only way in which force can be given to this proviso is to hold that the indemnity lands of the Atlantic and Pacific were exempted from the grant to the Southern Pacific, for, if not exempted, the former company's prospective right of selection would be to that extent impaired. It, must be borne in mind that these lands were in the granted . limits of the Southern Pacific, and that they are not lands in respect to which that company would have a right of selection, and might defer the exercise of that right until such time as suited it. Being within the granted limits of the Southern Pacific, all' its rights thereto vested at once, át the time of the filing of the map of definite location, and were not and could not be added to after that time; everything it;, could have in those-lands it had then, and at that time there was an existing prospective right on the part of the Atlantic and Pacific Company to make a selection. That prospective right would be impaired by the transfer of the title of a single tract to the Southern Pacific.' Hence, it follows. that the .title to none of these indemnity lands passed or could pass to the Southern Pacific Company.
In this aspect of the case it becomes unnecessary to inquire whether the lands described in the second' case were, sub judice or not. If they were sub judice, they could not. pass to either company; and if they were not, the Atlantic and Pacific's prospective right of selection prevented the passing of title to the Southern Pacific.
The decrees in both cases will be reversed, and the cases remanded with instructions to enter decrees in. favor of the government for the relief sought.