Zj. Xu et Hb. Ding, FORMATION AND DYNAMICS OF FEMALE AND MALE PRONUCLEI IN THE FERTILIZATION OF THE EGGS OF RANA-LIMNOCHARIS, Anatomy and embryology, 193(6), 1996, pp. 619-623
Eggs of Rana limnocharis were inseminated with conspecific sperm and t
he formation and timing of the second polar body, the formation of fem
ale and male pronuclei, and their dynamic movements were observed. Spe
rm enter the egg at random locations around the second polar body, bet
ween 15 degrees and 60 degrees.