154 CARL RICHARD MOORE. 



swimming forms are obtained after a short hypertonic treatment. 

 We can not account for it on the basis of a weak sperm suspension 

 because normal eggs with the same insemination gave 95 per 

 cent, of cleavages. Many times too but with no better 

 results an excessively heavy insemination has been used. 

 Standing for a short time before insemination "has no different 

 effect; indeed sperm retain their motility and actively swim 

 around in the dish several hours after insemination. The eggs 

 do not again return to the fertilizable condition by standing in 

 normal sea water at room temperature. Cytolysis is more rapid 

 than where membranes are retained and in the course of twelve 

 hours most of the eggs have gone to pieces. 



Neither has the percentage of fertilization ever been able 

 to be increased by the use of varying amounts of NaOH. 1 In 

 expe riments in which a few of the eggs did not produce mem- 

 branes as a result of the acid treatment, controls often show a 

 corresponding number of fertilizations. But in no case were 

 fertilizations increased by eliminating the membranes produced 

 after acid treatment. Even though membranes may possibly 

 exert some influence in keeping out accessory spermatozoa yet 

 this is not the essential block to fertilization. 



Obviously the eggs are not fertilized upon addition of sperm. 

 Can it be possible that yet some physical barrier exists at the 

 surface of the egg protoplasm? 



Cytological observation of such experiments have shown an 

 exceedingly interesting and significant situation. The obser- 

 vation will be presented in a very general way in the following 

 section. 



(c) Cytological Results of Optimum Butyric Treated Eggs. 

 Before presenting the data from a Cytological study it may be 

 well to dwell a little on the significance of such a study in rela- 

 tion to the partially antagonistic hypotheses, the lysin theory of 

 fertilization and the fertilizin theory. 



From the essential conceptions of the lysin theory obviously 

 we should expect no aberrant behavior either on the part of 



1 Loeb has shown that under certain conditions variable percents of NaOH 

 added to inseminated dishes materially aids in increasing the percentage of fertili- 

 zations. 



