200 TREUBIA VOL. II, 24. 
favourable breeding places newly formed in the vicinity, and to interpret 
such a phenomenon correctly. 
Indeed we get very little information concerning the only case observed 
by SCHÜFFNER, which occasioned SWELLENGREBEL (°°) to mention his 
second example of so called deviation of breeding places, in regard to the 
manner in which it was studied and to the observations made (cf. SWELLENG- 
REBEL (5%) page 47). SWELLENGREBEL (°°) indeed refers for this case to 
page 4 (this ought to be p. 78) of an other publication (°°), but in that 
place still less is said about the case in question. 
Now I do not mean to assert that the idea of the deviation of breeding 
places is wholly illogical, but I only hold, with DAMMERMAN (°°) that thus 
far no proofs and evidence have been adduced for the real existence of this 
so called deviation of breeding places. As there are no facts to go by, it 
is, however, difficult to further discuss SWELLENGREBEL (°*)’s “deviation 
of breeding places”. 
At all events, at present, there are at Batavia no breeding-places that can 
in any degree be compared with the empangs as regards productivity of 
ludlowi-mosquitos. 
VAN BREEMEN (°°) (page 64) remarks that the number of larvae, 
captured in places outside the marine fish ponds, from which /xdlowi- 
imagines developed is a vanishing quantity as compared with the masses 
of Zudlowi larvae produced by the empangs. 
‘Accordingly the incontrovertible fact remains that we shall never get 
rid of the endemic malaria plague of northern Batavia causing such a 
high mortality and paralysing the energy and productive capacity of the 
population, unless we start by making the whole Batavia brackish water 
zone harmless by a radical and efficient sanitation, including the draining- 
dry of the empangs. 
I speak‘ here jof sas radical and Jetiicient sanı tam omponemme 
whole Batavia brackish water zone and not only of the draining- 
dry of the empangs. Indeed, it should always be well borne in mind 
that not only the empangs but also all other pieces of brackish water 
containing floating algal masses and/or higher submerged aquatic plants, 
reaching up to the surface of the water, are genuine, highly dangerous 
breeding-places of /zdlowi. 
That pieces of fresh water, situated outside the Batavia brackish water 
zone and producing at present no /zdlowi-mosquitos would ever become 
productive breeding-places of /zdlowi in consequence of the draining 
of the empangs, seems, to say the least of it, highly improbable. At all 
events there are till now no facts known that could induce us to assume 
something like this. 
