▁of ▁sexual ▁ar ous al . ▁ ▁Ex perimental ▁studies ▁ ▁Vari ous ▁hypoth eses ▁and ▁theories ▁have ▁been ▁prop ounded ▁in ▁order ▁to ▁establish ▁the ▁bi ological ▁bases ▁for ▁sexual ▁ar ous al ▁in ▁humans . ▁Ivan ▁T ark han ov ▁showed , ▁in ▁experiments ▁on ▁cutting ▁and ▁artificial ▁empty ing ▁of ▁the ▁sem inal ▁ves icles , ▁that ▁the ▁latter ▁played ▁the ▁cru cial ▁role ▁in ▁the ▁generation ▁of ▁sexual ▁excitement ▁in ▁fro gs . ▁Pro ceed ing ▁from ▁these ▁experimental ▁results , ▁T ark han ov ▁put ▁forward ▁a ▁hypothesis ▁that ▁filling ▁and ▁ev acu ation ▁of ▁the ▁sem inal ▁ves icles ▁were ▁the ▁main ▁bi ological ▁cause ▁which ▁led ▁to ▁sexual ▁ar ous al ▁and ▁its ▁disapp earance ▁in ▁m amm als ▁and ▁humans . ▁Ever ▁since ▁T ark han ov ' s ▁find ings ▁demonstrated ▁sexual ▁ar ous al ▁in ▁fro gs ▁to ▁result ▁from ▁the ▁state ▁of ▁sem inal ▁ves icles , ▁the ▁attempted ▁el uc id ation ▁of ▁their ▁role ▁in ▁other ▁animals ' ▁sexual ▁behaviour ▁has ▁been ▁the ▁object ▁of ▁experimental ▁effort . ▁No ▁general isation ▁has ▁yet ▁appeared , ▁however . ▁The ▁study ▁performed ▁by ▁Beach ▁& ▁ ▁Wilson ▁( Univers ity ▁of ▁California , ▁Ber keley ) ▁in ▁ 1 9 6 4 ▁discovered ▁that ▁these ▁g lands ▁do ▁not ▁particip ate ▁in ▁the ▁reg ulation ▁of ▁sexual ▁ar ous al ▁of ▁male ▁r ats ▁in ▁the ▁similar ▁manner . ▁Whether ▁the ▁regular ity ▁observed ▁in ▁fro gs ▁is ▁applicable ▁to ▁humans ▁remains