424 



Ralph S. Lillie 



in some manner to result in changes leading to the initiation of 

 development. 



After-treatment with cyanide also acts favorably in the case of 

 eggs that have been warmed in normal sea-water without previous 

 exposure to cyanide solutions. The following experiments will 

 illustrate: 



TABLE XII 



September g, igoj. Eggs were removed at IO:lS a.m. and the majority began to mature. After 4^ 

 minutes they were warmed in normal sea-water to J5° jor JO seconds. One portion (A) was then 

 transferred to normal sea-water; a second portion {B)to o^ffo ^^^ solution, and from this portion 

 were transferred at the following intervals to sea-water 



A portion of eggs fertilized with spermatozoa about one hour after removal gave a good proportion of 

 larvae; largely small and thick-walled or otherwise abnormal. The eggs were thus not especially favor- 



able. 



The proportion of eggs developing to blastulae and farther, 

 while not large in the above series, was decidedly increased by the 

 after-treatment with cyanide, and development proved both more 

 rapid and more nearly normal in eggs thus treated. The best 

 conditions were found in Experiments 4 and 5. Too prolonged 

 after-exposure to cyanide affects the egg injuriously, the propor- 

 tion of abnormal larvae being greater in Experiment 5 than in 

 Experiment 4. 



A repetition of this experiment, with a larger range of exposure 

 to cyanide, gave a similar result (Table XIII). 



