1905.] Effects of Alkalies, etc., on Eggs of Echinus. 



115 



Table V. — Ammonium Hydrate. 

 Experiment 1, Brood No. 3. 



No. 



Amount of 

 ammonia in 

 decinormal 

 solution, 

 added to 

 200 c.c. of 

 sea-water. 



Amount of 

 added alkali 

 in the 

 solution, 

 expressed as 

 a fraction 

 of normal 

 strength. 



Observations of embryos at stated times after commencement 

 of experiment. 



2 hrs. 



16 h. 30 m. 



1 



Control 





2 



- 5 c c. 



-00025 



3 



0-75 „ 



-00037 



4 



10 „ 



0-0005 



5 



1-5 „ 



-00075 



6 



2-0 „ 



o-ooi 



Division into two cells com- 

 mencing 



Same as control 

 Same as control 

 Same as control 

 No division 



Blastulse. Twenty to twenty- 

 four cells in circumference 



Blastulse. Twenty cells in cir- 

 cumference. A few morulse 



Same as No. 2 



Same as No. 2 



Half morulas and half blastulse 

 Same as No. 5 



Experiment 2, Brood No. 6. In this series blastulae formed with smaller 

 number of cells in embryo. 



No. 



Amount of 

 ammonia in 

 decinormal 

 solution, 

 added to 

 200 c.c. of 

 sea-water. 



Amount of 

 added alkali 

 in the 

 solution, 

 expressed as 

 a fraction 

 of normal 

 strength. 



Observations of embryos at stated times after commencement 

 of experiment. 



18 h. 30 m. 



42 hrs. 



1 



Control 





Four-celled, many morulse 



All stages to early blastulae 









and a few early blastulse 



2 



1 c.c. 



0-0005 



Two-, three- and four-celled, 



Morulse, at all stages 









and morulas 





3 



2 n 



o-ooi 



Many single - celled, and 



Early and late morulse. Ex- 









stages up to early morulse 



trusion of cell contents from 









cells 



4 





-0015 



Nearly all single cells 



No further development. Ex- 











trusion of cell contents 



