FRESH-WATER FISHERIES OF CEYLON. 101 
only be based upon a close familiarity with local conditions. Each 
river system and each tank area have to be treated separately on 
their own merits. Illegitimate fishing, such as the use of poison 
and dynamite and the wholesale damming of water-courses, does 
not usually take place in the vicinity of towns, but in more or less 
remote tributaries. On the other hand, the destruction of young 
fishes in paddy fields is a matter which calls for special attention, 
and reference should be made on this subject to the Report on 
Pisciculture in South Canara, by H. 8. Thomas, Collector of South 
Canara, 1870, a copy of which has been procured through Govern- 
ment at my recommendation for the Museum Library. The point 
which requires comprehensive discussion is the destination of the 
waste water from paddy fields. If this water flows back into a river, 
or into an irrigation canal, the inundated paddy fields act as an 
efficient nursery for young fishes, provided that they are allowed 
free scope and are not trapped prematurely. Under such conditions 
a system of paddy fields is the model for a combined hatchery, 
nursery, and stock pond. 
Artificial fertilization and hatching require hatcheries and stock 
ponds which would be useful for re-stocking, with due discrimina- 
tion, both village tanks and city tanks. Replenishing the supply of 
fishes means turning immature fishes into fishable waters, where 
they can continue to grow to a marketable size; unfortunately no 
size is too small for curry. But if Government undertook this work, . 
somebody would have to pay and be paid. Recourse to artificial 
fertilization may be unnecessary in certain cases where the seasons 
and localities of natural spawning are known. I have published in 
Spolia Zeylanica, Part XXIII., December, 1909, an account of my 
observations on the nesting habits of lula, the principal fresh-water 
food-fish of Ceylon, though not the largest. I am now in a position 
to add that an allied species of Ophiocephalus, also used extensively 
as food and as bait for larger fishes, namely, O. punctatus, called 
““madaya” or “mada-karaya,” makes its nest amongst inshore 
rushes, though without the definite clearing that lula prepares, and 
in such spots, where there is an abundance of microscopic food for 
the ensuing fry, it deposits pale amber-coloured eggs with a single 
glistening oil-globule, which float at the surface like the eggs of lula, 
from which they could hardly be distinguished unless their parentage 
was known. I had seen a shoal of very young fry of “* madaya ” 
accompanied by their parents in a paddy field “* wala ” at Bellana, 
near Matugama in the Kalutara District, in April, 1908 ; and on 
October 29, 1909, I saw a nest of the floating eggs in the Hunupitiya 
arm of the Colombo lake, behind Bishop’s College, close to the shore. 
where there was a great quantity of the spherical aggregates of the 
colonial infusorian, Synura. I brought away some of the eggs and 
hatched them out, feeding the fry, after the yolk had been absorbed, 
on lake plankton, which I collected myself. 
