SUNIER: Marine fish-ponds of Batavia. 2715) 
In contradistinction to what was shown by the /zdlowi females, the 
number of rossii females produced in this case continually increased with 
the increase of the salinity from 0 to 29.9°/,,. On this ground it seems 
to me that the influence of the rise of the salinity on the production of 
ludlowi was as a matter of fact greater than appears at first sight from the 
above figures concerning Heemraad Oost. 
It also stands to reason that it is not possible for me, whenever the 
average number of /udlowi2Q2 produced per 10 M? and per night does 
not vary just so as could be expected in connection with the salinity 
variations alone, to specify exactly why this is so, especially not when the 
ludlowi production at different salinities differs but little, as for instance in 
the case of the ponds near Jaagpad. For of course the exact magnitude 
which in any specified case the /xdlowi production must attain is the 
resultant of the conjuncture of a great many factors whose influence to a 
great extent escapes our observation. 
However the regular decline of the /zdlowi production in connection 
with the gradual rise of the salinity is unmistakably expressed in the figures 
collected in Table XI which deal with the entire Batavia empang district. 
In my opinion the figures mentioned after a in Table XI have the 
best claim to give a true picture of the average production of /udlowi 
females per 10 M? and per night for the whole of the Batavia empang 
belt at different salinities. As stated in Table XI these averages to be 
found after a were obtained by determining for each salinity class the 
average of the local averages calculated for the different parts of the 
Batavia empang zone. By doing so an equal influence is given to each local 
average in determining the final average of the production for the entire region. 
Now in Table XI we see these averages placed after a, denoting the 
production of Judlowi QQ per 10 M? and per night, gradually decreasing 
as the salinity rises. The average production is greatest at the lowest 
salinities, and it is reduced to nihil at a salinity a little over 40 °/,, (scil. 
at 42.8°/,, (cf. Tables VII and V)). 
According to the figures placed after A in Table XI simply denoting 
the averages derived at once from all the data collected in the entire 
Batavia empang zone at a given salinity, the /zdlowi-production would be 
at its maximum not at the very lowest salinities, but at salinities between 
10 and 19.90/,. Also the figures put down in Table VII in respect of 
Pekulitan and Pegantungan seem to point in the same direction. After a 
careful study of Table V it has become clear to me that the fact of the 
ludlowi-production being, at least in some cases such as those of Pekulitan 
and Pegantungan, smaller at salinities between 0 and 9.9°/,, than at 
salinities between 9 and 19.9°/,,, should be accounted for as follows: 
The lowest salinities between 0 and 9.9°/,, I found, as may be readily 
understood, especially in the early part of the year after the heavy showers 
of the West monsoon had fallen. 
