252 TREUBIA VOL. II, 2—4. 
Number of pulsa- 
| Consecutive number of 
the heart-beat synchron- Number of > = 
Moment of Time | izing with the moment pulsations in (Wh BEE a 
of time marked in 10 seconds. aaa) y 
| the first column. 
! 
O (Seconds) Wy messen | 
| 3 18 
10 Seconds 3 
20 120 
20 Seconds | 23 
| Di | 126 
30 Seconds | 44 | 
| 24 144 
40 Seconds | 68 | 
| 24 | 144 
50 Seconds | 92 
| | 
After arresting the heart by moving the egg to and fro with two needles, 
the egg in the last table and a few other kepala timah eggs artificially 
fertilized and 8 times 24 hours old, usually showed the first heart-beat 
again after 2 to 4 seconds. 
It afterwards became clear to me that the first-discussed egg, found 
in a tuft of Chaetomorpha taken from an empang, and in which distur- 
bances acted so powerfully on the number of heart-pulsations, was not a 
normal one. When I made the experiments afore mentioned with this egg, 
Fig. 31, A young kepala timah (Haplochilus panchax (HAM. BUCH.) ) 
just out of the egg-capsule, seen from the dorsal side. X 20 !/,. 
it was from a comparison with artificially fertilized eggs, older, and con- 
siderably older than 8 days, from the moment.of fertilization. This embryo 
was then far less active and energetic than other embryos 8 or more than 
8 times 24 hours old. Furthermore 6 times 24 hours later, i.e. when it was 
considerably more than 14 times 24 hours old it had not yet disclosed, and 24 
hours later again I ascertained that the embryo had died inside the egg-capsule. 
Eventually it appeared to me that the number of heart-beats to the 
minute may vary considerably even in embryos of the same age. Thus the 
number of pulsations per minute of 3 embryos, 8 times 24 hours old, from 
artificially fertilized eggs of Haplochilus panchax, was 145, 148 and 164 to 167. 
