FERTILIZATION REACTION IN ECHINARACHNIUS PARMA. 21 



washed seven times, agglutination tests and inseminations being 

 made at each washing. The table gives the data. 



EGGS FROM OVARIES OF THREE FEMALES. 



Began with 4 c.c. of eggs, ended with 2 c.c. 



Two points are worthy of note respecting this table: First, 

 the amount of water used in washing was unfortunately not the 

 same throughout; and second, which is unavoidable, the quantity 

 of eggs diminished with each washing. These two factors suffice 

 to account for apparent irregularities in per cent, of cleavage and 

 in agglutination. Thus, nos. I and 2 give the same per cent, 

 of cleavage, whereas in no. 2 the agglutination reaction is but 

 half as strong, but it is also true that twice as much sea-water 

 was used in no. 2. The time between the washings is likewise 

 irregular; this presumably would affect the amount of agglutinin 

 present in the sea-water. However, the end result is unmis- 

 takable: low fertilization and low agglutination reaction are 

 parallel. Since freshly made sperm suspensions were used for 

 each insemination, the only other possible explanation is that 

 the eggs die in large numbers. This is rather hazardous if not 

 gratuitous since the eggs may make abortive attempts at develop- 

 ment. 



3. Eggs Normally Resistant to Fertilization. 



On July 15 I procured 7 c.c. of dry eggs which were placed in 

 65 c.c. of sea-water. Also, by placing ovaries in sea-water for a 

 few minutes before straining I obtained 3 c.c. of eggs which seemed 

 to be unusually fine. Eggs from both lots were inseminated for 

 preservation of a normal series. To my chagrin relatively few 

 of these eggs segmented. July 16 gave similar results. Not 

 until later did experiment reveal the cause of this failure to 



