SUNIER: Marine fish-ponds of Batavia. 271 
fact that water of a low salinity could be admitted into those ponds 
from the mouth of the Gunung Sahari canal (cf. Chapter Il). 
We accordingly observed that most of the Batavia empangs in which 
the salinity had risen after the end of June 1918 to a point far above 
that of sea-water, produced no more /zdlowi in the latter half of 1918, 
whilst on the other hand the ponds of Heemraad Oost in which the 
salinity continued even then far below that of sea-water, went on 
producing /zdlowi. 
It was this observation that was really the inducement of our 
collecting the data laid down in Table IV, which data have already 
partly come up for discussion in Chapters Il to Vl and have been further 
elaborated in Tables V to XI. 
Table V arranges the salinities and the quantitative data concerning the 
Anophelines caught by means of the mosquito-nets or emerged from the 
collected larvae and pupae, 1° topographically, that is, according to the 
particular part of the Batavia empang zone where they were collected; 2° in the 
order of the salinities. In order to render the nightly catches in mosquito-nets 
mutually comparable they have wherever necessary been computed out 
for 10 M? of the surface area of the more or less dense submerged vege- 
tation, in connection with the fact, as communicated above, of 10 nets 
being usually set simultaneously in one breeding-place. For each 10 °/o, 
of the salinity the reader then finds computed the average number of 22 
of Myzomyia ludlowi THEOBALD and of Myzomyia rossii GILES captured 
per 10 M? and per night. Only in the case of the data collected for sali- 
nities between 20 and 24.9°/,, and between 25 and 29.9°/,, the Anopheline 
averages have been computed for the just mentioned classes of 5°), 
of the salinities. I did this after I had perceived that with salinities 
between 30 and 40°/,, far fewer /udlowi were produced by the Batavia 
empangs than with salinities ranging from 20 to 30 °/o). It is evident that 
the object of this subdivision was to find out whether a considerable 
diminution of the production of /udlowi could be ascertained already when 
the salinity rose above 25°/,,. These Anopheline-averages have then been put 
together in Table VII A and B. In these Tables a computation has been made 
in two ways for the several classes of 10°/,, or 5°/o9 salinity, of the aver- 
age Anopheline production per 10 M? and per night for the whole of 
the Batavia empang belt; scilicet in the first place by averaging again, for 
the divers 10°/,, and 5% salinity-classes, the averages for the various parts 
of the whole Batavia empang zone; and in the second place by each time 
striking the average between all the data collected throughout the entire 
Batavia zone of marine fish-ponds for the several 10°/,, and 5°/,, salinity 
classes. 
From the nature of the case no averages could be determined of the 
data occurring in Table V relative to the Anophelines emerged from the 
larvae and pupae collected from the empangs, as the separate catches of 
