DISTRIBUTION OF SUBSTANCES IN SPERMATOZOON. 



253 



sea-water. The changes shown diagrammatically in Fig. n are: 

 (a) A noimal spermatozoon; (b) Initial changes in the arrange- 

 ment of lipochromatic substance; (c) The nucleus swells a little 



FIG. ii. Behavior of the spermatozoa of Arbacia in egg-water; intra-vitam 

 staining with Janus green. See text. 



and moves towards the base of the head. At the same time the 

 lipochromatic substance divides into two, a part follows the 

 nucleus, covering it, another part remains in the region of the 

 basal ring. Thus one can see in fresh preparations on the con- 

 necting region of the spermatozoa two transversal dark zones, 

 between which there is a refractile one. On stained preparations 



