432 THE ZOOLOGIST. 
time of year when spawning occurs? whether this is deleterious to 
the parent? the size of the eggs, their colour; whether they float 
or sink, are deposited in running or stagnant waters? whether 
they are covered or left uncovered in their nests? whether the 
male carries them about or protects them? and whether their 
germination can be retarded by artificial means or natural causes, 
as by the action of cold or their immersion in mud ? 
That anadromous forms, as the Salmon or Shad of Europe, 
or the Shad (Clupea palasah) of India, migrate from the sea to 
the fresh waters to deposit their eggs in localities most suitable 
for their reception, is well known. If we examine into the migra- 
tion of Indian fishes for breeding purposes we find this takes place 
with three classes, viz.—(1) anadromous forms from the sea to the 
fresh waters, as already referred to; (2) species which may be 
considered to pertain to the mountains, or else deposit their ova 
in the rivers of the hills; (3) those which are restricted to the 
plains, but which likewise undertake certain changes of locality at 
these periods. 
Of the migratory hill fishes the various forms of large Barbels, 
termed ‘‘ Mahaseers,” furnish good examples. In the Himalayas 
they ascend the main rivers, but turn into the side-streams to 
breed; while on the less elevated Neilgherry mountains, in the 
Madras Presidency, the same phenomenon occurs, but with this 
difference, that they deposit their ova in the main streams, because 
these are small, owing perhaps to their never being replenished 
with snow-water. Occasionally the fish are too large to ascend 
these mountain rivers, when it would appear they breed at the 
bases of the hills; whether it is from the offspring of these that 
this genus has extended through the plains it is not my present 
purpose to inquire. When the rivers commence being in flood 
adult fish are able to ascend to feeding grounds previously 
inaccessible to them. Having spawned, they keep dropping 
gently down stream, during which time the amount of water is 
diminishing; thus the ova, when hatched, are completely cut off 
from the locality where the parent fish reside, precluding their 
making a meal of them. The fry, therefore, have the heads of 
the rivers to themselves in perfect security, and each torrent 
becomes transformed into a small stream intersected by pools, 
where they can remain until the next rains enable them to descend 
to the larger rivers. 
