“ Such is the contention here, the plaintiffs insisting that the fees are collected partly for inspecting oysters and partly for the cost of policing the waters of Chesapeake bay; while the defendant insists that the charge is collected and spent solely for inspection.
2. Inspection necessarily involves expense, and the power to fix the fee, to cover that expense, is left primarily to the legislature, which must exercise discretion in determining the amount to be charged, since it is impossible to tell exactly how much will be realized under the future operations of any law. ”

“ But when the facts show that what was known to be an unnecessary amount has been levied, or that what has proved to be an unreasonable charge is continued, then they are obliged to act in the light of those facts, and to give effect to the provision of the Constitution prohibiting the collection by a state of more than is necessary for executing its inspection laws. In such inquiry they treat the fees fixed by the legislature for inspection proper as prima facie reasonable, and do not enter into any nice calculation as to the difference between cost and collection ”

“ The unreasonableness of inspection fees may appear from the language of the act, as in D. E. Foote & Co. v. Clagett, 116 Md. 228, 81 Atl. 511, where a charge of 2 cents a bushel on oysters was collected, under a statute which provided that one half was to be used for inspection and the other half was to be used for replacing shells on the natural beds for the purpose of increasing the oyster crop. That law was declared void by the court of appeals of Maryland, because of the provision that one half of the inspection fee should be applied to other than the inspection purpose. ”