SUNIER: Marine fish-ponds of Batavia. 101 
A and B of Map II a great deal of Najas was to be seen growing in water 
which at the time showed a salinity of less than 3!/, 0/9. On June 27th 
following the Najas had practically disappeared from those ponds, the 
salinity then amounting to 26.4°/ in pond A and 30.4 °/o) in pond B. 
Between March 5th and June 27th I observed the presence of Najas falciculata 
R. BR. in the ponds A and B at the following salinities: 
Pond A of Map II Pond B of Map Ii 
5 Ill "18 i Si Mee < 3, Yoo 
19 Ill 18 Gre andes ODE 
3 IV ’18 12.40 9%, an 
16 IV ’ı8 10.9, Ofer NS 
27 IV ’18 Behe Oleg 13.0 °/oo 
14 V 18 14.45 and 21.1 fo 16.7 Joo 
DS VL AUS Walle Olea 19.1 foo 
15 VI 18 DLO AS DE Nias 
27 VI ’18 26.4 Fo 30.4 990 
In this case of the ponds A and B the slow decay and perishing of 
the Najas falciculata vegetation began in reality as early as April 16th, 
but this may very likely have been owing largely to the fact that the ponds 
were by that time quite filled up with submerged vegetation and contained 
little water, the proprietor not being able to conduct more water into the 
ponds A and B just then. 
When soon after the end of June 1918 the high salinities mentioned 
in Table I began to appear in the ponds A and B, not a trace of Najas 
was any longer to be found in those ponds. On the other hand Najas 
falciculata immediately made its appearance again after the salinities had 
become reduced in February 1919. 
Similarly I came upon a good deal of young Najas falciculata on 
April 3rd 1918, in pond G of Map II, the water in which showed salinities 
ranging between 7.5 %/ and 14.3 Joo. As the salinity rose I found live 
Najas falciculata in this pond for the last time on July 16th, 1918; the 
salinity being 31.7 °/oo. 
During the period from April 3rd to July 16th, 1918, I found Najas 
falciculata alive in this pond at the following salinities: 
3 IV 18 7.5 "loo 
16 IV 718 16:70 
27 IV ‘18 23.6 Joo 
Ja NIS AA 
28. UNIS 20.1.5, 
DA N TS DS 
| 
16 VII ’18 SHA ES 
