Top ⇑Two Former Techniques and Their Associated Views of Ovum Production
Using Only "Mature Ova"
This technique is based upon the hypothesis that females produce only one clutch of eggs each reproductive season. Researchers who have adopted this technique have counted and measured only the relatively large "mature ova" in the ovaries of preserved females, under the assumption that they represent the single clutch of eggs to be produced in that year.
Just which intra-ovarian cells comprise "mature ova" is not always defined or defined with sufficient specificity to allow other researchers to determine exactly which cells were counted and measured. A composite list of descriptive characteristics from an umber of reports gives the following general description of "mature ova": transparent or translucent, yellow to orange, one or more oil droplets, chorions elevated, occur in ripe females, tend to be concentrated near center of ovary, and easily detached from surrounding tissue.
Using Both "Immature Ova" and "Mature Ova"
Under the assumption that females produce more than one clutch of eggs each reproductive season (year), some researchers have counted the relatively small "immature ova" in addition to the larger "mature ova," representing all easily visible gametic cells within an ovary. This approach also is based on two additional assumptions. First, that all cells within the ovaries of each female are spawned in an undetermined number of clutches during the course of one reproductive season; Second, that no additional cells begin development during the reproductive season; therefore, the maximum possible number of eggs is set at the beginning of the reproductive season.