SUNIER: Marine fish-ponds of Batavia. 165 
The part of the fish-pond district belonging to the Residency of Batavia, 
between Kamal and Marunda is represented on Map I. All of it, except 
the eastern part stretching for 1!/, K.M. from East to West, was prepared 
from the Topographical Service map (1:50.000), brought up to date until 
May Ist 1918. All the names of localities mentioned in the text below 
are to be found on Map I. WA 
A little east of the Muara Karang there is a system of marine fish- 
ponds, belonging to Mr. M. H. Th. Görs, where in early March 1918 
MR. VAN BREEMEN and I began the systematic gathering of data concern- 
ing the biology of the empangs in connection with the problem of malaria- 
prevention. A sketch-map of this group of ponds (assessment number 
(verpondingsnummer) 3238 Batavia) was prepared by my assistant MR. E. 
C. A. HERBST. It is to be found on Map Il. The point marked P on this 
Map II is marked in the same way on Map I. 
Like nearly all the other marine fish-ponds in the neighbourhood of 
Batavia, Mr. Görs’s empangs are rectangular. Their sizes vary, as far 
as I could make out, between a few square metres (fry-ponds) and + 15 
bahus '). They are nearly. always very shallow; when a coolie waiks in 
a sea-fish-pond, the water, even in the deepest places, seldom reaches to 
his hips, mostly no higher. than a little above the knees. Along the mar- 
gins the ponds are usually deeper than near the centre, as the laying out 
is begun by digging a ditch all round, which continues to be afterwards 
more or less regularly dredged. In the construction of large ponds two 
more ditches are dug, intersecting at right angles, each one connecting the 
centres of two opposite sides of the rectangular pond. In a number of 
places the ponds can be made to communicate by means of little sluice- 
gates (photo no. 1, Plate VI) with one another and with the canals that 
connect them with the sea. 
For further information about the ine out of the ponds the reader 
is referred to numbers 3, (6,) 17 and 25 of the literature-list: 
The embankments and earthen dams or walls between the system of 
ponds belonging to Mr. Görs are mostly treeless (cf. photos 3, 4, 5 and 13 
(Plates VIII, IX, X and XXI)). In a few places only they are planted with 
coconut palms, as may be seen in photos 6 and 7 (Plates XI and XIII), 
which however represent another group oi ponds, that of Ang Sun Hian 
near Kampong Fluit. 
Along the edges of the ponds, on a level with the surface of the water, 
there grows very abundantly a grass, Paspalum distichum L., belonging to 
the Paniceae. This grass is a halophyte or salt-indicator, and is recogniz- 
able from afar by its blue-green tint. When, as sometimes happens, parts 
of the fishponds begin to fall dry, those parts are frequently entirely over- 
grown with Paspalum distichum L.. Besides this salt-indicator, the following 
1) A bahu is 7096!/, square metres. 
