FERTILIZATION OF THE FROG'S EGG 



75 



^\M. l}'.' 



Oviposition and fertilization in Rcina. (A) Egg-laying posture of Rana 

 clamitans, just prior to the onset of oviposition: dorsal view. (B) Upstroke of the 

 male and the appearance of the first batch of eggs. (C) Downstroke of the 

 male and the formation of the surface film: dorsal view. (D) Typical amplexus 

 in Rana clamitans: lateral view. (E) Pre-release motions of paired Rana pipiens. 

 (Courtesy, Dr. L. R. Aronson, American Museum of Natural History.) 



