370 
No. of Eggs Failures 
No. 20, 1885, Dec. 5th, Male hybrid (No. 12), 
young, and Lochleven ... : x -- 7,000 78 per cent. 
No. 21, 1886, Dec. 5th, Male hybrid (No. 12), 
young, and British char Eos .- 12,000 99 " 
No. 22, 1887, Nov. 10th, Male hybrid (No. 12), 
adult, and fontinalis ... ae .- 14,000 86 " 
No. 23, 1884, Nov. 12th, Hybrid (No. 9) and 
Lochleven ae .. 1,850 100 " 
No. 24, 1887, Nov. 15th, Fated ‘Wo. 12), and 
Lochleven oe wea wets a -» 3,000 90 h 
Before investigating the foregoing 24 instances of hybridiza- 
tion, and the percentage of loss among the eggs, I must draw 
attention to the fact that there always exists a greater percentage 
of mortality among the eggs from young mothers, or from the 
young in their earlier stages.* This seems to be consequent 
upon deficient vitality, while we likewise, especially among 
hybrids, observe many deformities. This loss among the eggs 
being caused in some instances by the immaturity of the parents, 
is seen among the hybrid char, or those raised from fontinalis 
and British forms. Thus in three instances, when the young 
hybrids were intercrossed, the loss averaged 84 per cent. 
among 12,746 eggs, but when the parents were a year or more 
older, it sank to an average, in three experiments, of 55 per 
cent. The difference in the mortality, in the two sets of 
experiments, must be attributed to the age of the parent 
fishes. 
At present this hybrid breed seems to be prolific, the 
original parents being closely allied, both pertaining to the 
* Among many instances I select the following :—November 13th, 1884, 
about 500 eggs, having the diameter of 0°17 of an inch, were obtained from a 
rising 2-year-old Lochleven trout at Howietoun. They were fertilized from 
another of the same race of mature size. About a dozen hatched, and of 
these only seven lived up to May. On November 29th, 1883, 4,500 eggs of 
Lochleven (of the season of 1875) were milted from a salmon par a little over 
24 years old, and I have already shown that, although amongst the eggs the 
mortality was only about 6 per cent., out of 3,700 only 100 were alive at the 
end of the year. 
