300 NATHAN FASTEN. 



EXPLANATION OF PLATE II. 



FIG. 24. Spermatozoon which has exploded in a hypotonic solution of calcium 

 chloride. 



FIGS. 25 to 28. Spermatozoa which have been exposed to various concentra- 

 tions of potassium chloride. 



FIGS. 29 to 31. Spermatozoa in weak solutions of potassium hydroxide. 



FIGS. 32 and 33. Spermatozoa which have exploded in distilled water. 



FIGS. 34 to 39. Spermatozoa which have been subjected to the effects of ovarian 

 fluids. 



FIGS. 40 to 43. Spermatozoa which have been acted on by glacial acetic acid 

 in sea water. 



FIG. 44. Bottom view of spermatozoon which has been exposed to saponin in 



sea water. 



FIGS. 45 and 46. Spermatozoa .which have been acted on by nitric acid in 



sea water. 



