ER TREUBIA VOL. II, 2—4. 
empangs in water of salinities between 40 and 84.6 °/o9, against 3055 rossii- 
females only 2 dudlowi females emerged, one at a salinity of 41.3 %/oo 
and one at a salinity of 44.6 °/oo. The latter case slightly shifts the limit of 
maximum salinity for the production of Zudlowi, which as we have seen 
before was according to the catches in mosquito-nets at 42.8 °/5, and is 
now shifted to 44.6 0/6. 
The data concerning the production of /zdlowi and rossii by the 
empangs at salinities higher than 40 °/, were obtained, as Table V shows, 
exclusively at the end of 1918 and for a small part also at the very 
beginning of 1919. 
We were enabled to collect these data in consequence of the fact 
that 1918, at least after February, was a very dry year (cf. also Chapter II) 
as becomes apparent from the following table of data supplied by the 
Royal Magnetic(al) and Meteorological Observatory at Weltevreden, in which 
the figures denoting a fall of rain lower than the long period average are 
printed in italics. 
Rainfall in millimetres. 
I. Tandjong Priok. 
— 
Months aa ll il IV |V | vı|vulvalıx | x | XI) XU 
ak ANR A ER ere 2. | _._ 
19 years average \339/360/170/101/ 90) 85| 57, 41| 61, 68| 120/171 
1917 * 13551777136) 51| 25| 18\ 59| 20| 98/107) 50) 223 
1918 317) 733) 59 | 61) 39) 17) 4114 6) .0| 43109234 
1919 196| 464 181| 75 136, 75| 2| 63, 65) 33| 68|126 
ll. Weltevreden (Observatory). 
Months | I | Il a | \ V | VI vit van IX) X | XI | XII 
42 years average | 318/323] 207 136/111] 99 Al 43) 75/116 148) 191 
1917 451) 353) 763|224| 55) 49 114) 94 149) 223) 78) 212 
1918 321/657) 700|109| 84| 14) 38) 27| 11| 16 131| 146 
1919 205) 480) 109) 124/159/195 25) 80) 75 708,105) 90 
_ These figures exhibit a conspicuous difference between the second 
half of 1917 and of 1918. Whilst the second half of 19!8 was very dry, 
there was in the second half of 1917 in the Batavia empang region a 
