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dug a trench in the gravel, through which he caused a current of 
water to flow, two inches deep. He then had these two living 
fishes held in this trench side by side, while with the hands he 
pressed the ova and milt out of their bodies, which mixed freely 
together in the stream. A few minutes subsequently he 
removed the ova to a stream to which no other fish had access, 
and ninety-four days subsequently young fish were hatched. 
Passing on to a paper read by Mr Suaw before the Royal. 
Society of Edinburgh, December 18th, 1837, he observed that 
his former paper on ova taken from the Nith had been objected 
to, as there was not sufficient evidence that these were the eggs 
of the salmon, the same stream being accessible to other fish. 
So he repeated his former experiments, preserving the skins of 
the parent fish, also laying his experimental basins dry, not 
only for the purpose of removing any young fish which might 
remain, but likewise to fit them up on such a principle as would 
exclude the possibility of confusion, either from the over- 
flowing of the ponds themselves, or from the flooding of the 
river Nith, on the banks of which they were situated. On 
January 4th, 1837, he captured a pair of salmon engaged in 
depositing their spawn. Before proceeding to take the fish he 
formed a small trench in the shingle at the edge of the river, 
through which he directed a small stream of water two inches 
deep. At the end of this trench he placed an earthenware 
basin of considerable size for the purpose of ultimately receiv- 
ing the ova. Having drawn the fish ashore he placed the 
female, still alive, in the trench, and pressed from the body a 
quantity of the ova. Then the milt was similarly obtained 
from the male, thoroughly impregnating the eggs. The eggs 
were now transferred to the earthenware basin, and deposited 
in a stream connected with a pond previously formed for its 
reception. On the 28th of April, or 114 days after being 
removed from the parent fish, the eggs hatched. On May 24th, 
_ or twenty-seven days after being hatched, the young had 
absorbed the yelk-sac; they died a few days subsequently, 
caused, he supposed, from a deposition of mud, the same result 
having been more than once produced when the pond had not 
been sufficiently embedded with gravel. 
