1905.] the Development of Eggs of Plaice and Echinus. 141 



My best thanks, in conclusion, are due to Professor Herdman, F.E.S., 

 to whose kindness I am indebted for the material for these experiments, 

 and for permission to work at the station, and to Professor Moore, for his 

 kind and valuable criticism and assistance throughout. 



Table I. — Comparison of Percentages of Deaths in Fresh Eggs. Eggs of 

 2 days old and eggs of 10 days old, with varying quantities of deci- 

 normal NaOH and HCl. 





After 

 6 days. 

 Fresh 

 eggs. 



After 

 7 days. 

 2 days 

 old. 



After 

 7 days. 

 10 days 

 old. 



After 

 10 days. 

 Fresh 

 eggs. 



After 

 11 days. 

 2 days 

 old. 



After 

 11 days. 

 10 days 

 old. 



Control, 200 c.c. sea- 

 water. 



5-0 







2-0 



25 -0 







2-4 



(9 days) 



1 "0 c.c. decinormal NaOH 



1 -5 



2 -0 



2 -5 



3 -0 



4-3 

 9-6 

 25 -0 

 18 -2 

 27 3 

 44-0 













 2-6 

 12-7 

 25 



4-2 



2- 9 

 0-9 



3- 

 2-5 

 9-4 



31 -8 

 31 -8 

 48-0 



2 6 

 14 -5 

 48-2 



2 5 

 26 '9 

 (10 days) 



1 - c.c. decinormal HCl... 



1- 5 „ „ ... 



2- „ „ ... 

 2-5 



3 



4-0 „ „ ... 



10-0 

 

 8-6 

 19 -0 

 33 -3 

 75 -0 



3 3 

 8-0 

 3 

 20 -0 

 39 -3 

 39 -4 



2-2 

 4-8 

 1 -5 

 3 3 

 1-7 

 1 -8 



28 -6 

 33 -3 

 75 -0 



26 -2 

 42 -4 

 39 -4 



4 6 



5 5 



Average, exclusive of 

 Control 



22 -9 



12 -8 



3-2 



41-4 



28 -9 



9-9 



