of fire insurance rates with exemption
for farmers mutuals, German Alliance Ins. Co. _v._ Lewis, 233 U.S. 389
(1914); different requirements imposed upon reciprocal insurance
associations than upon mutual companies, Hoopeston Canning Co. _v._
Cullen, 318 U.S. 313 (1943); prohibition against life insurance
companies or agents engaging in undertaking business, Daniel _v._ Family
Ins. Co., 336 U.S. 220 (1949).

_Intoxicating liquors:_ exception of druggists or manufacturers from
regulation. Ohio ex rel. Lloyd _v._ Dollison, 194 U.S. 445 (1904);
Eberle _v._ Michigan, 232 U.S. 700 (1914).

_Lodging houses:_ requirement that sprinkler systems be installed in
buildings of nonfireproof construction is valid as applied to such a
building which is safeguarded by a fire alarm system, constant watchman
service and other safety arrangements. Queenside Hills Realty Co. _v._
Saxl, 328 U.S. 80 (1946).

_Markets:_ prohibition against operation of private market within six
squares of public market. Natal _v._ Louisiana, 139 U.S. 621 (1891).

_Medicine:_ a uniform standard of professional attainment and conduct
for all physicians, Missouri ex rel. Hurwitz _v._ North, 271 U.S. 40
(1926); reasonable exemptions from medical registration law, Watson _v._
Maryland, 218 U.S. 173 (1910); exemption of persons who heal by prayer
from regulations applicable to drugless physicians, Crane _v._ Johnson,
242 U.S. 339 (1917); exclusion of osteopathic physicians from public
hospitals, Hayman _v._ Galveston, 273 U.S. 414 (1927); requirement that
persons who treat eyes without use of drugs be licensed as optometrists
with exception for persons treating eyes by the use of drugs, who are
regulated under a different statute, McNaughton _v._ Johnson, 242 U.S.
344 (1917); a prohibition against advertising by dentists, not
applicable to other professions, Semler _v._ Oregon State Dental
Examiners, 294 U.S. 608 (1935).

_Motor vehicles:_ guest passenger regulation applicable to automobiles
but not to other classes of vehicles, Silver _v._ Silver, 280 U.S. 117
(1929); exemption of vehicles from other States from registration
requirement, Storaasli _v._ Minnesota, 283 U.S. 57 (1931);
classification of driverless automobiles for hire as public vehicles,
which are required to procure a license and to carry liability
insurance, Hodge Drive-It-Yourself Co. _v._ Cincinnati, 284 U.S. 335
(1932); exemption from limitations on hours of labor for drivers of
motor vehi