14 



E. E. JUST. 



of 15 per cent. 2.5 M KCr and removed. Samples taken as 



follows : 



No. 1 10:3s 



" 2 10:50 



" 3 ii:os 



" 4 11:20 



" 5 11:40 



" 6 12:00 



" 7 1:2s 



These gave the next day swimming forms as follows: 



No. I 4 per cent 



2 7 



3 4 



4 2 



5 2 



7 3 



(d) On August 17, eggs were washed by changing the water six 

 times in five hours then subjected to 15 per cent. 2.5 M KCl in 

 sea-water, samples being taken at sixty minutes and thereafter 

 at five-minute intervals. One tenth per cent. (.1%) was the 

 best result after sixty minutes in the KCl sea-water. 



(e) Combination of KCl with Heat} — An experiment of last 

 summer was repeated except that dry eggs were used and the 

 minimum exposure, five minutes, of the series the only one tried. 

 The protocol follows: 



August 17, 1:25 P.M. Dry eggs are put in 10 c.c. of 15 per 

 cent. 2.5 M KCl in sea-water for five minutes; jelly formation 

 almost at once. Eggs are then placed in 50 c.c. of sea-water at 

 35° C. Four lots removed to 100 c.c. of sea-water as follows: 



No. I i:ss 



" 2 2:00 



" 3 2:0s 



" 4 2:10 



The next day, at 10:30 A.M., the percentages of swimming 

 forms, largely unsegmented found were as follows: 



No. I (25 minutes' exposure to heat) 3 per cent. 



" 2 (30 " " " " ) 7 " 



" 3 (35 " ) 27 " 



" 4 (40 " " " " ) 25 " 



1 It will be recalled that AUyn used a combination treatment of KCl and heat on 

 the egg of Chceloplerus with rather different results from those mentioned here with 

 Nereis. Her method however, was different. 



