190 NRE BANVOEN Ne 
Just as for Chaetomorpha and Ruppia we must bear in mind also in 
this case, that the data do not permit the inference that (within the limits 
of the salinities observed: less than 3!/,°/,,—84.6 °/ 9) the salinity has any direct 
bearing upon the occurrence of Enteromorpha in the Batavia empangs. 
From the observation-table (Table IV) it appears that on February 
6th 1919, in a pond near Kampong Jaagpad, Enteromorpha was met with 
in water possessing a Salinity of 3.4 °/.,. Similarly there is an entry about a 
pond near Muara Karang, to the effect that on May 19th, 1919 Enteromorpha 
occurred there in water of 5.45 °/,, salinity. On the other hand the same 
table shows that in the Batavia empangs “young green Enteromorpha” was 
found at a salinity of 54.6 °/)) (23 XI ’18; Jaagpad), and 
“fresh, already rather thick Enteromorpha” at a salinity of 
43.6 Jo (25 XI ’18; Muara Karang). Moreover in some 
experiments with the little fish Æaplochilus panchax (HAM. 
BUCH.), to be discussed in Chapter VI, Enteromorpha kept 
well and alive in pond water whose salinity, originally 
amounting to 60.0 Jo) had risen to 108.0 °/g) in twenty-two 
times 24 hours by evaporation of the water. 
As a fourth component of the submerged vegetation 
in the Batavia empangs I must mention the Najadacea 
Najas falciculata R. BR. This plant was determined for me 
by the Botanist for the Java-flora, Mr. C. A. BACKER, who 
also forwarded a few flowering stems of the material 
supplied by me to Dr. A. B. RENDLE, London, which 
specialist confirmed Mr. BACKER’s determination. 
Figure 6 pictures part of a young leaf of Najas fal- 
ciculata magnified about 40 times. 
At Batavia Najas is called by the Malay name of 
“sanggang”, a name which seems, however, to be given 
also to other higher submerged aquatic plants. 
Najas falciculata is very common in the Batavia em- 
pangs, but temporarily disappears whenever the salinity 
exceeds about 30 °/ '). When afterwards the salinity 
decreases again, Najas falciculata is soon observed to 
reappear in the same places where it used to be found 
before the increase of the salinity. 
When Mr. VAN BREEMEN and myself started collecting 
with regularity both data and materials at the Batavia em- Fig. 6. 
pangs, in March 1918, we found Najas falciculata in a of Nae voren 
great many ponds. Thus on March 5th 1918 in the ponds R.Br. from the Ba- 
tavia empangs. x 40. 
1) Some time ago (56) I spoke in this connection of 20 to 25/9. I was then thinking 
more particularly of the highest salinity permitting Najas falciculata to keep alive for 
any length of time. This question can however not be answered without definite cult- 
ture experiments. I must therefore confine myself here to the question of the highest- 
salinities at which I still found Najas falcieulata alive in the Batavia empangs. 
