184 TREUBIA VOL. Il, 2—4. 
October 28th 1918, and on April 17th 1919, The masses of algae, however, 
very soon grow upwards until they reach up to just beneath the surface of 
the water. They may also sometimes get loose from the pond-bottom, 
when they come floating up against the surface of the water. Together | 
with the other water-plants to be mentioned below they may fill up large 
parts of the ponds, as shown in our photos 2, 3, 4, 6, 8, 9, 14 and 15 
(Plates VII, VIII, IX, Xi, XIV, XV, XXII and XXIII). 
_Chaetomorpha masses are not seldom seen to emerge just above the 
surface of the water, the filaments appearing above the water then not 
being of a lovely green, but of a lemon-yellow hue. I very often had the 
impression that this rising above the surface was connected with the pro- 
ducton of oxygen bij the masses of Chaetomorpha, which would seem to 
be lifted up bij the numerous little gas-bubbles occurring between the filaments. 
On the submerged vegetation reaching up to just under the surface of the 
water, consisting of Chaetomorpha and of the other plants to be named below, 
there lives often quite a complex flora of smaller forms in the Batavia empangs, 
partly overgrowing or coating the separate Chaefomorpha filaments, 
partly extending over the entire submerged vegetation. Among these forms 
Schizophyta play a very important part. 
There are, to begin with, forms like Oscillatoria, Lyngbya and Nostoc, 
frequently overgrowing the entire submerged vegetation with a filmy layer. 
Sometimes the upper side of the submerged vegetation is coloured red by 
the presence of a Chroöcoccacea, which | think ought to be looked upon as a 
Gloeocapsa species (perhaps Gloeocapsd sanguinea ENGLER & PRANTL ()). 
This Gloeocapsa | invariably met with on quite old submerged vege- 
tations. 
Among the forms that grow round the separate Chaetomorpha-fila- 
ments I think I have perceived in the first place Chamaesiphonaceae 
(ENGLER & PRANTL (!°) ), Chlamidobacteriaceae (Streptothrix-like forms) and 
also Diatomaceae. Dr. CH. BERNARD further informed me that on filaments 
of a sample of Chaetomorpha which | sent to him, he had found a My- 
coideacea. To a specialist familiar with the systematics of these forms 
the coated (or overgrown) Chaetomorpha-filaments would present ample 
scope for investigation. As a result of this coating the old Chaetomorpha- 
filaments are often of a dark brown or nearly black. Some further details 
concerning the coating or overgrowing of the Chaetomorpha-tilaments are to 
be met with in the observation-table. (Table IV). 
With the forms that 'overgrow the submerged vegetation are immediately 
related the forms collectively referred to at Batavia by the name of 
„tay-ayer” (— “water turd”). This ,,tay-ayer’-vegetation develops at the 
bottom of the empangs, especially when this bottom has been laid dry for 
a couple of days. !) 
1) Confer also Chapter V. 
