132 



THE AMERICAN ARBACIA 

 TABLE lo 



EFFECT OF VARYING THE CENTRIFUGAL FORCE ON TIME TO BREAK AND SIZE OF HALVES 



E. B. Harvey, 1941a 



TABLE II 



SIZE OF HALVES WHEN CENTRIFUGED IN HYPO- AND HYPERTONIC SEA WATER 



E. B. Harvey, 1943 



Whole egg 

 Sea water Diam. Vol. 



White half 

 Diam. Vol. 



Red half 

 Diam. Vol. 



Nucleus Per 

 Diam. Vol. cent 

 (X (j.^ broken 



Eggs in hypo- and hypertonic sea water, then centrifuged 10,000 x gfor 4 minutes 



60% 82.4 (292,900) 70.4 (182,700) 58.0 (102,200) 16.0 (2,145) 10% 



80% 74.9 (220,000) 62.1 (125,400) 56.3 (93,400) 12.8 (1,098) 20% 



100% 72.0 (195,400) 59.0 (107.500) 56.0 (91,950) 1 1.5 (796) 70% 



125% 66.6 (154,700) 51.7 (72,360) 53.8 (81,540) 9.6 (382) 98% 



Recovery in 100 per cent sea water 



6o%-ioo% 72.0 (195.400) 59-2 (108,600) 55.7 (90,480) 1 1.2 (736) 



8o%-ioo% 72.0 (195.400) 59-2 (108,600) 54.7 (86,170) 1 1.5 (796) 



100% 72.0 (195,400) 59.0 (107,500) 56.0 (91,950) 1 1.5 (796) 



i25%-ioo% 72.0 (195,400) 56.3 (93.940) 57.6 (100,060) 11.2 (736) 



The return of whole eggs to normal size is approximately perfect, as 

 found also by McCutcheon, Lucke, and Harthne, 1931, p. 402. 



c. Single Salt Solutions. Plate XV 



Eggs were kept for 40 minutes in solutions of different salts isosmotic 

 with the sea water, 0.52 M NaCl, 0.53 M KCl, 0.34 M CaClg, 0.37 



