152 



OTTO GLASER. 



appearance of the membrane would have to be attributed to the 



hypotonic treatment itself, should be capable of fertilization by 



means of the sperm-infected medicine dropper. Actually under 



these circumstances fertilization with only 4 to 5 spermatozoa 



visible in the optical equator is possible in a considerable number 



of eggs. 



Protocol. 



In a watch crystal 3 volumes of sea-water +3 volumes of dis- 

 tilled. Added i volume of an egg-suspension in normal sea- 

 water. At the instant' when the first indications of membrane 

 "initiation" were noticeable added 3 volumes of "double sea- 

 water," i. e., sea-water whose volume had been reduced one-half 

 by boiling. By means of a sperm-infected pipette every egg was 

 provided with 4 to 5 spermatozoa. In a series of microscopic 

 fields the number of undivided eggs was later compared with the 

 number that had divided. The results were: 



Controls: Normal eggs-j- usual amount of sperm = 100% Fertiliz- 

 ation. Eggs treated as above-}- usual amount of sperm =100% 

 Fertilization. This is in sharp contrast with the earlier experi- 

 ments in which the operations were carried out at the same 



