THE CALIFORNIAN SALMON. 
69 
owners, having been included in the territory ceded to 
Germany after the last war. 
The ova when received at Huningue, is placed in artificial 
hatching beds, until the process of incubation has advanced 
to a certain stage, which is found by practical experience 
to be the safest time to subject the eggs to the rather 
rough usage to which they are sometimes liable, in 
being forwarded long distances. If they are roughly 
handled, or meet with any violent concussion at an early 
stage of the existence of the embryo, or immediately after 
the impregnation of the eggs, the vital principle is very 
easily extinguished. But when the hatching has proceeded 
till the embryo is clearly visible in the egg, they will bear 
being transported to long distances without injury. When 
the ova are about to be deposited in the natural way in 
the redd, the female fish excavates a hollow by fanning 
away the loose gravel with her tail fin. It is well known 
that divers can lift stones under water, in building sub- 
marine walls for piers, docks, &c., which they could not 
move on land, on account of their weight being less in 
water, by the weight of the bulk of water which they 
displace, and this principle enables the salmon to excavate 
their redds in loose gravel, in a strong current, with little 
difi&culty. 
The redd can be easily recognised by those familiar with 
its appearance, being simply a mound containing about a 
barrowful of gravel, thrown up into a little heap, with a 
hollow or furrow at the upper side, where the work was 
finished. When fish are spawning, it is no unusual thing 
for other fish of the same species to lie in wait, and devour 
the eggs in a wholesale way, and many of the ova are 
carried away by the current into deep water, where they 
cannot be hatched out and must perish. Many ova are 
never impregnated, and the enemies and dangers to which 
