SUNIER: Marine fish-ponds of Batavia. 253 
This latter remark also holds for Haplochilus javanicus for which I 
found the following numbers of heart-beats in embryos a little over 6 times 
24 hours old. 
Eggs of Haplochilus javanicus (BLKR.). Number of heart-beats 
Embryos a little over 6 times 24 hours old per minute 
a 148 — 150 
b 153 
€ 168 
d 173 — 175 
e 188 — 189 
A considerable time after | had completed this Chapter VI, as far as 
it is found above, SYBRANDI’s (3’) paper in De Tropische Natuur, Part II, 
page 133 ff, came to my notice and i found that among other things it 
also dealt with Haplochilus panchax (HAM. BUCH.), 
For Haplochilus panchax (HAM. BUCH.) SYBRANDI (?’) mentions, 
besides the Malay name of “kepala timah”, also the Sundanese appellat- 
ion of “sisik malik” and the Javanese “pitak”, but he does not 
give the name “wader tjeto”, which, as I have mentioned, would be 
the name given to our kepala timah in Central Java, according to 
GRONEMAN (2). 
SYBRANDI (*7) too has observed that the eggs of Haplochilus panchax 
(HAM. BUCH.) are attached to water plants. He writes: “The female attaches 
the fairly large eggs to aquatic plants by means of a viscid thread these 
eggs possess”. Now it is apparent from my figures 20 and 21 (and from my 
figures 22—30 after eggs of Haplochilus javanicus (BLKR.)), that especially 
when the eggs get a little older, several adhesive threads twisted into a 
string, may to the naked eye make the impression of a single (bigger) 
thread; for which compare also my remarks on fig. 21 above. 
SYBRANDI (°7) says that the development (within the egg-capsule) of 
the kepala timah takes about 7 days. As I stated above, at my laboratory, 
under the conditions described by me, 8 out of 12 artificially fertilized 
kepala timah eggs came out after more than 8 and less than 9 times 24 hours 
after fertilization. 
What SYBRANDI (37) says concerning the food of the kepala timah 
tallies exactly with what I communicated about it in the foregoing. 
SYBRANDI (*7) writes as follows: “They” (scil. the kepala timah) “are extremely 
