Recent cases 206 Taxes on net income 208 Miscellaneous taxes affecting interstate commerce 209 Vessels 209 Airplanes 210 Motor vehicles 211 Public utilities: Regulatory charges 213 Dominance of Congress 214 McCarran Act: Regulation of insurance 214 Police power and foreign commerce 215 Origin of police power 215 State curbs on entry of foreigners 216 State quarantine laws 217 State game protection and foreign commerce 217 Police power and interstate commerce 217 General principles 217 State regulation of agencies of interstate commerce 220 Railway rate regulation 220 Adequate service regulations 221 Safety and other regulations 221 Invalid State regulations 222 State regulation of length of trains 223 Lesson of Southern Pacific Co. _v._ Arizona 225 State regulation of motor vehicles: Valid regulations 226 Invalid State acts affecting motor carriers 227 Transportation agencies 228 Navigation; general doctrine 228 Bridges, dams, ferries, wharves 230 Ferries 231 Telegraphs and telephones 231 Gas and electricity 233 Foreign corporations 234 Miscellaneous 234 Banks and banking 234 Brokers 235 Commission men 235 Attachment and garnishment 235 Statutory liens 235 Police power and the subject matter of commerce 235 Scope of the police power 235 Quarantine laws 236 State inspection laws 237 State prohibition laws: The original package doctrine 238