276 TREUBIA VOL. II, 2—4, 
Except in the ponds of Heemraad and Heemraad Oost into which 
water of low salinity can be continually admitted from the mouth of the 
Gunung Sahari canal (cf. Chapter Il), salinities below 10°/,) were not 
observed by us in the latter half of 1919 (cf. Tables V and VII). 
Salinities comprised between 10 and 19.9 °/,, on the other hand generally 
occurred somewhat later in the year than salinities between 0 and 9.9 °/,). 
Thus in the ponds near Fluit, Pegantungan and Pekulitan in July 1919 
I found almost exclusively salinities between 10 and 19.9 °/,,, whilst salinities 
below 10°/,, though observed in these ponds in March and April and 
even in May and June, no longer occurred there in July. 
Now it appears from many examples that, at least during the first 
seven months of 1919, generally speaking more /udlowi were produced at 
a specified salinity according as that salinity occurred later in the year. 
Below I have put together a few of those examples borrowed from Table V: 
ne oe he wear: Average number of lud- 
Salinity : Ponds near: JE ue 92 produced per 
(1919) 10 M?-and per night. 
0—0.00/, Pekulitan March 20—23 7 
5 May 28 — June 25 34! |, 
5 Jaagpad February 6 — 21 0 
à 5 Juni 3 — 6 25 
2 Heemraad April 23 6 
er 5 July 24 — 25 460 
A similar example, likewise borrowed from Table V, but referring to 
salinities between 10 and 19.9°/,0, is furnished by the following figures 
relating to the empangs near Jaagpad. These ponds produced in 1919, 
at the salinities mentioned: 
between April 10th and 22nd: an average of O ludlowi p. 10 cM? and p. night; 
1 July Ath „ 18th ” 1) „ 28!], > » 3) 1 „ ” 7 
Trying to give an explanation of the fact that on the whole more; 
ludlowi are produced at the same salinity in June and July than let us say 
in February, March and April, I must start by pointing out that, as I des- 
cribed in Chapter II, the low salinities are produced suddenly, generally 
in January or February in consequence of the heavy West-monsoon showers, 
accompanied or not by river-spates and inundations. In the period immedi- 
ately preceding the falling of those West-monsoon rains the /zdlowi 
production, at least in our case, that is in the autumn of 1918, had very 
markedly decreased in the greater part of the Batavia empang region in 
connection with the very strong increase of the salinity and had even 
been reduced to 0 in not a few cases. 
