* Produce sperm under the influence of the [[Endocrine_System_-_Pituitary_Gland_-_Anatomy_%26_Physiology|pituitary gland]].
* Produce sperm under the influence of the [[Endocrine_System_-_Pituitary_Gland_-_Anatomy_%26_Physiology|pituitary gland]].
−
* Often a rudimentary [[Female_Reproductive_Tract_-The_Ovary_-_Anatomy_%26_Physiology|ovary]] nearby in the male.
+
* Often a rudimentary [[Female_Reproductive_Tract_-The_Ovary_-_Anatomy_%26_Physiology|ovary]] (known as the Bidder's organ)nearby in the male.
−
** Alows males to transform into females if the female population is scarce.
+
+
=== Bidder's Organ ===
+
+
* Bidder's organ is a spherical, brownish organ in toads.
+
* The organ is located just in front of the kidney, or, mesonephros.
+
* It is formed at the cranial tip of the male and female gonad during the larval stage.
+
* Normally it is inactive and contains miniature follicles which have the capability to mature (becoming active).
+
* When the female population is scarce, the Bidder's organ enlarges and produces viable oocytes and then gonadotropins, which stimulate the growth of the Müllerian ducts to form uterus and oviducts.