ABSTRACT
In the analysis of events immediately preceding and following fertilization of the frog egg, it is frequently desirable to treat the eggs with various reagents. Any such treatment must circumvent the barrier represented by the fertilization membrane and the jelly layers. These membranes can be removed from fertilized eggs mechanically or by treatment with proteolytic enzymes (Spiegel, 1951) without impairing development. However, unfertilized eggs from which the jelly has been removed mechanically cannot be fertilized by sperm unless the jelly is restored, and chemical removal of the jelly also inhibits their ability to be parthenogenically activated (Barch & Shaver, 1959). Therefore an alternative method for obtaining jelly-free eggs for treatment prior to fertilization is necessary.
