83 
IV. The Java Sea; Strait Sunda. 
On my return to Batavia in the beginning of July, I had the 
opportunity of spending a fortnight at the newly established marine 
Laboratory there. I beg to tender here my most cordial thanks to 
the director of the laboratory, Dr. A. L. J. Sun i er, for his unsur- 
passed hospitality and his untiring efforts for facilitating my work, 
the main object of which was to extend my studies on the larval 
development of Echinoderms. Owing to various circumstances (a. o. 
the destruction of a diatom culture, which I had brought along with 
me from home, and the impossibility of starting new cultures, be- 
cause the Chemical solutions which I had also brought along with 
me to this end, proved to be impure and therefore killed the or- 
ganisms instead of stimulating their growth) my efforts were not 
crowned with quite satisfactory results. The larvæ of Diadema 
setosum and Linckia miliaris were reared, but the former not beyond 
the first stage, and the latter not so far that it could be ascertained 
whether this larva — which is of the usual Bipinnaria-form — passes 
through a Brachiolaria-stagQ. That the larva of Diadema setosum 
proved to be closely similar to that of Diadema antillarum is only 
what was to be expected. Another Echinoid, Echinothrix Desori, 
which lives in numbers on the riff at the little Island Edam out- 
side Batavia, was found to have no ripe sexual products by this 
time of the year. 
From the 26th of July to the 8th of August I had the privilege 
of partaking in a trip to the Java Sea, West of the Thousand Islands, 
and in the Sunda Strait with the G. S. “Brak”, undertaken with 
the object of carrying out investigations for the Batavia Laboratory. 
In the time left from this research work I was allowed to make 
dredgings and thus had a most welcome opportunity of studying 
the bottom fauna in this area and of making comprehensive col- 
lections, which was the more desirable, as very little work of this 
kind has been done, since Professor C. Ph. Sluiter made his 
important investigations about half a century ago; upon the whole, 
so extensive investigations have never been undertaken here. Slui- 
ter’s work was, as far as the dredgings are concerned, mainly 
confined to the Bay of Batavia and — according to kind information 
in a letter — to the part of the Sunda Strait between the town of 
Anjer and the Island “Dwars in den weg” (about the area indicated 
6* 
