520 SEALE. 



Usually the area of the large pond is much greater. The dikes of the 

 small ponds are low, often not 30 centimeters above the water level. 

 These smaller ponds are of about equal size, being usually rectangular 

 and each of about 200 square meters in area. The palaistaan are fonned 

 by throwing up dikes. The main dikes are large, especially along the 

 banks of the so-called "river" or estero, where mangrove trees frequently 

 are planted for their protection. The water from the estuary is per- 

 mitted, when the tide is flowing, to enter one of the smaller ponds 

 through a sluice {pirinza) usually constructed of masonry with two 

 gates, one of several slides of solid wood for controlling the water and 

 the other of close bamboo jjalings to prevent the egress of the baiigos 

 and the ingress of undesirable tenants such as carnivorous fishes and 

 crabs which burrow into the dikes and cause leakage. Snakes and birds 

 are also evils that have constantly to be guarded against. 



This small pond distributes the water suppty to the others and is 

 used for capturing the marketable hangos. It is usualh' separated from 

 the larger pond by a close paling of bamboo aroimd the narrow opening 

 in the partition dike. Wlien it is desired to capture the fish in the 

 largest pond, the paling is removed and a strong current is caused 

 to flow from the smaller pond to the larger. The bangos attracted by 

 the fresh water swim against the current and enter the smaller pond in 

 great numbers, where they are readily captured in a seine. This opera- 

 tion is often accomplished about midnight, so that the fish will be 

 exposed in the Manila markets in the best condition. 



The remaining two j^onds, or subdivisions of the ftond area inclosed 

 witliiu the limits of the boundary dikes, are connected with each other 

 and with the pond which feeds the water by single pij)es made of the 

 hollow log of the luyong (Diospyrus nigra Eetz). These tubes are 

 called palah'unhungan, the water and fish being controlled at these 

 openings by a solid wooden plug or a funnel of bamboo strips. The 

 water in these two small ponds is kept at a depth of but a few decimeters, 

 the ponds being used interchangeably for cultivating the food alga 

 {Oedogonium) and for developing the hatvaghawag. (Fig 2.) 



FOOD or THE BANGOS. 



If it is desired to cultivate the food alga (the large pond is originally 

 stocked in the same way), the water is allowed to drain off and the 

 clay is exposed to the full power of the sun. The alga rapidly makes 

 its appearance and a little water is then permitted to cover the bottom. 

 This is gradually increased as the Oedogonium develops. 



The Oedogonium seems to thrive best upon a clean clay (kaolin). 

 If the bottom is covered with a deposit of dark mud and in old ponds 

 where a black, evil-smelling deposit has formed, it is scraped clean with 



