154 ArtiFIcIAL PARTHENOGENESIS AND FERTILIZATION 
The reader will notice the striking difference in the behavior 
of NH,OH and NaOH. Low concentrations of NH,OH (0.5 
c.c. per 50 c¢.c. solution) raise the rate of oxidations in the 
fertilized egg almost to the maximal height and a further rise 
in the concentration has only a slight effect upon the rate of 
oxidation. Low concentrations of NaOH raise the rate of oxi- 
dation only a little, and the efficiency of NaOH rises steadily 
with an increase in its concentration. We could not go beyond 
the concentrations used in this experiment, since the addition 
of 3¢.c. N/10 NaOH to 50 c.c. m/2 NaCl+KCl+CaCl, leads 
already to a cytolysis of the eggs. 
It is also of interest to point out that in the eggs of S. pur- 
puratus fertilization by sperm raises the rate of oxidation to 
about five or six times the amount of that in the unfertilized 
eggs. This seems to indicate that with NH,OH it is not pos- 
sible to raise the rate of oxidations in the unfertilized egg 
beyond the limit to which it can be raised by the fertilization 
with sperm. It is not possibile to decide whether the same 
holds true for NaOH. 
The fact that a base reaches its maximum effect at so low 
a concentration is not confined to NH,OH but is also shared 
by the amines as the following table shows. NH,OH and 
ethylamine were compared. : 
TABLE XXVIII 
| Conrricrent or ACCcCEI- 
B ERATION OF OXIDA- 
AmounrtT OF Basse ADDED TO TIONS IN 
50 c.c. m/2 (NaCl+ KCl1+ 
CaChL) 
NH,OH | Ethylamine 
Onive: caN /NOke eect a!) 1.4 
OFZ CCPN NOES sere 2.9 3.0 
OcArcics N/1OSe seeceenee 3.4 4.3 
DES CIN Ore oo pn eloe 3.9 4.2 
Ethylamine reaches its maximal efficiency at the concentra- 
tion of 0.4 ¢.c. base to 50 c.c. of the neutral liquid; and for 
