PLATE 6 
EXPLANATION OF FIGURES 
18to25 Show theeffects of removal of the jelly by centrifuging on the spermato- 
zoon attached to the egg. It willbe noticed that the cone in this and the following 
plates, though just as well defined as the preceding, stains differently. The 
behavior of the cone is the same, however. 
18 Entire spermatozoén present, drawn out to band. History: centrifuged 
7200 revolution in thirty-five seconds, fifty minutes after insemination; preserved 
immediately. 
19 The middle-piece and part of the base of the spermatozoén have been 
removed by the jelly. The protoplasm surrounding the cone has been raised in a 
protuberance, which happens not infrequently (cf. fig. 22). History same as fig. 
18. : 
20 to23 These figures show removal of increasingly large portions of the sperm 
head by the jelly. Each drawing from a single section of aseparate egg. History 
same as fig. 18. 
24t025 Toshow effects of removal of jelly by centrifuging after penetration has 
begun. History same as fig. 18. 
466 
