660 STUDIES IN GENERAL PHYSIOLOGY 
Thirteenth series.—It was evident that the KCl brought 
about artificial parthenogenesis, even if the osmotic pressure 
of the sea-water was not raised. I now tried whether a pure 
KCl solution was able to cause artificial parthenogenesis, 
and whether this was possible when the osmotic pressure of 
such a solution was lower than that of sea-water. The solu- 
tions used were as follows: 
(1) 10 cc. 24n KCl+ 90 cc. distilled water 
(2) 20 iT3 “ + 80 “ iT9 
(3) 25 “ it9 + 15 “ 6c 
(4) 2 «+98 sea-water 
(5) Normal sea-water (control) 
The osmotic pressure of solutions 1 and 2 was smaller 
than that of normal sea-water. One portion was left thirteen, 
the other fifty minutes in these solutions. 
The next morning a large number of swimming trocho- 
phores was found in every one of the dishes that contained 
eggs taken from the first four solutions. The control solu- 
tions were absolutely free from trochophores. 
Fourteenth series— The experiment was so surprising 
that I wished to repeat it. The following solutions were 
prepared: 
(1) 10cc. 24n KCl + 90 cc. distilled water 
(2) 2ec. “ “+ 98 c.c. sea-water 
(3) Normal sea-water (control) 
The eggs were left in the solutions fifty minutes. The 
water was sterilized. The next morning the eggs that had 
been in solutions 1 and 2 contained living larve, while the 
eggs in the normal sea-water were undeveloped. 
Fifteenth series.— I wished next to know whether the KCl 
solution might be still more diluted without annihilating its 
effect upon the unfertilized Cheetopterus eggs. Four solu- 
tions were used: 
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