194 
the succeeding rains enable them to descend, and at this 
period fresh parent fish repeat the operation of the previous 
year. 
The season at which breeding occurs varies with the family 
of fish and the locality. This again is susceptible of further 
modification, in accordance with the temperature and perhaps 
composition of the water, the amount of food procurable, and 
many other local circumstances. Likewise there is some con- 
dition in the fish itself, respecting which we know but little, 
but which plays its part. It is easy to understand that during 
very cold winters breeding is usually late, which may be partly 
occasioned by the ova taking longer to hatch, as well as by the 
parent fish being later depositing its eggs. The period at 
which the Salmonide in these isles breed may be roughly esti- 
mated (except under exceptional circumstances) at from the 
commencement of September until the middle of January or 
February. In 1866 some brook trout eggs were despatched 
from Hampshire and Buckinghamshire to Tasmania, and the 
first young reared in the Antipodes formed their redds in July, 
1869, or during the coldest season of the year. Sir Humpurey 
Davey observed in Southern Austria that he found charr just 
ready to breed in the summer, and he came to the conclusion 
that the waters at that time must be of a temperature best 
fitted for the purpose. In Sweden Arrepr remarked that the 
salmon spawned in the middle of the summer. Dr Heysnam, 
in Cumberland, stated that they prefer breeding in the warmer 
streams, leaving the snow-fed ones until later on. Mr Harviz- 
Brown, at Loch Gorm. in Sutherlandshire, which is greatly fed 
by snow water, has taken trout heavy with ova in June and 
July. But easy as this theory would be in order to explain the 
different months fishes select for breeding purposes, there exist 
many exceptions which are still open to discussion. Some 
rivers are stated to have early and others late breeds of salmon. 
A correspon dent of the Field, writing from Devonshire, February 
2, 1884, observes, upon having taken out of his trap two pairs 
of spawning trout, one of the males being nearly 2 lb. in weight. 
One pair had partly deposited its ova exactly in the same spot 
— 
| 
| 
