[8] Stanley Hall and Allin, "Tickling and Laughter," _American Journal of
Psychology_, October, 1897.

[9] H.M. Stanley, "Remarks on Tickling and Laughter," _American Journal of
Psychology_, vol. ix, January, 1898.

[10] Simpson, "On the Attitude of the Foetus in Utero," _Obstetric
Memoirs_, 1856, vol. ii.

[11] Erasmus Darwin, _Zoönomia_, Sect. XVII, 4.

[12] Hyades and Deniker, _Mission Scientifique du Cap Horn_, vol. vii. p.
296.

[13] Such an interpretation is supported by the arguments of W. McDougall
("The Theory of Laughter," _Nature_, February 5, 1903), who contends,
without any reference to the sexual field, that one of the objects of
laughter is automatically to "disperse our attention."

[14] Even the structure of the vaginal mucous membrane, it may be noted,
is analogous to that of the skin. D. Berry Hart, "Note on the Development
of the Clitoris, Vagina, and Hymen," _Transactions of the Edinburgh
Obstetrical Society_, vol. xxi, 1896.

[15] W.H.B. Stoddart, "Anæsthesia in the Insane," _Journal of Mental
Science_, October, 1899.

[16] Gina Lombroso, "Sur les Réflexes Cutanés," International Congress of
Criminal Anthropology, Amsterdam, _Comptes Rendus_, p. 295.