34 



RALPH S. LILLIE 



TABLE 1 



July 4, 1912: 10.30 a.m. The eggs from several starfish were placed, about one-and- 

 a-quarter hours after removal from the animals, in 0.55 tn. NaCl solution. After 

 five minutes in this solution they were returned to seawater. Part of the eggs 

 remained permanently in sea-water {for control). The rest, ten minutes later 

 were placed for thirty minutes in the several solutions of the series; they were then 

 returned to sea-water. Next morning the proportion of mature eggs that had 

 formed blastulae was approximately estimated. The results were as follows: 



AFTER-TREATMENT 



CONDITION NEXT MORNING 



1. None (Control treated with 0.55m. NaCl 

 alone) 



2. Hypertonic sea-water (250 cc. sea- 

 water + 30 cc. 2.5m NaCl) 



3. Sea-water + m/lOOO KCN 



4. Sea-water + 0.6 vol. % ether 



5. Sea-water + 0.1 % chloral hydrate 



6. Sea-water + 0.2 % ethyl urethane 



7. Sea-water one-tenth saturated with 

 chloretone 



Only one living blastula found; almost 

 all eggs dead 



Blastulae few though increased in num- 

 ber, — ca. 1 % of mature eggs 



Marked increase in blastulae: 25-30 % 

 of mature eggs 



Well-marked increase: ca. 10-15 % 



Well-marked increase: ca. 10-15 % 



Less favorable: ca. 2-4 % 



Considerable increase: ca. 5 %' 



Fertilized control. Eggs fertilized one-and-a-quarter hours after removal 

 yielded a large proportion of normal larvae. 



Unfertilized control. Eggs left in sea-water without treatment: next morning 

 all mature eggs are dead and coagulated, without membranes or cleavage. 



TABLE 2 



July 6: 3.38 p.m. Eggs were placed about one hour after removal from the animals 

 in 0.55m NaCl solution for five minutes, then returned to sea-water and after 

 ten minutes placed in the following solutions for thirty minutes, then again re- 

 turned to sea-water. The results were as follows: 



Controls. Eggs fertilized one hour after removal developed normally. 

 fertilized eggs were all dead and coagulated next morning. 



Un- 



