The London Medical Record of 1884 quotes Jdanoff of St.

Petersburg in mentioning a soldier of twenty-one who had a supernumerary testicle erroneously diagnosed as inguinal hernia.

Quoted by the same reference, Bulatoff mentions a soldier who had a third testicle, which diagnosis was confirmed by several of his confreres.

They recommended dismissal of the man from the service, as the third testicle, usually resting in some portion of the inguinal canal, caused extra exposure to traumatic influence.
Venette gives an instance of four testicles, and Scharff, in the Ephemerides, mentions five; Blasius mentions more than three testicles, and, without citing proof, Buffon admits the possibility of such occurrence and adds that such men are generally more vigorous.
Russell mentions four, five, and even six testicles in one individual; all were not verified on dissection.

He cites an instance of six testicles four of which were of usual size and two smaller than ordinary.
Baillie, the Ephemerides, and Schurig mention fusion of the testicles, or synorchidism, somewhat after the manner of the normal disposition of the batrachians and also the kangaroos, in the former of which the fusion is abdominal and in the latter scrotal.