Fish including cyclostomes, elasmobranchs, and teleosts display a wide variety of ways of coping with the stringent conditions they encounter in the aquatic environment. This diversity is especially evident in the female genital systems where some fish spawn profligate numbers of small eggs while others develop a few yolky eggs that may receive parental care. Parental care is carried to extremes in viviparity where eggs develop within the ovary or oviducts of the mother. This volume describes the myriad ways in which fish have approached problems of reproduction it is an amply illustrated comparative study of the microscopic structure of the female genital systems of fish. The timing of its appearance is auspicious in that it coincides with the decline of the golden age of descriptive morphology. It is a compilation of thousands of micrographs mostly electron micrographs from classic works in the field and should prove valuable to investigators studying fish in areas such as ecology, physiology, and reproductive biology who may view histology as essential in their work but have little background in this area. It includes chapters on the origin of genital systems, the structure of ovarian follicles, mechanisms of ovulation, the cortical reaction, oviducts, oviparity, and amazing examples of viviparity.