TRANSACTIONS OF SECTION D. 1061 
May 1885, when they commenced springing out of the pond; and on one being 
opened it proved to be a female with the eggs developing, and had it lived it 
would evidently have bred this winter when about forty-four months of age, or at 
a similar period to the female smolt of the pure salmon. But, unfortunately, owing 
to the severe drought which the country suffered from during the last summer, 
the stream ceased to give an adequate supply, and all. but two of the 144 fish 
were found dead. Milt and roe were developing in almost all, and although this 
experiment has not been successfully completed, it so far demonstrates that 
hybrids between the male salmon and female trout are fertile at the same period 
ag are pure salmon. . 
In Leuchart’s case the trout was the male element, and his fish commenced 
breeding near the end of their second year, as is the case with trout. At Howie- 
toun, where the salmon was the male element, the hybrids would have commenced 
breeding at about the same period as in the salmon. It would therefore seem 
probable that the male elements in both cases had been prepotent, and also that 
when the male element in the hybrid has been the anadromous salmon, the young 
at the breeding season attempt to migrate seawards, and they have not lost their 
anadromous instincts. 
Some more hybrids, similar to the foregoing as regards parentage but only one 
year old, are at Howietoun, and it is hoped will in due course arrive at maturity. 
A set of experiments were likewise instituted at Howietoun into the question of 
whether the age of the male parent has any direct influence on the health of the 
hybrid progeny. On November 29, 1883, about 4,500 eggs from a Lochleven 
trout of the season of 1875 were milted from a salmon par thirty-two months old. 
The eggs hatched well, but the majority of the young were affected with dropsy of 
the yelk sac, from which nearly all succumbed before the end of the year. That 
this dropsy was owing to deficiency in vitality is rendered probable by an experi- 
ment I tried at Cheltenham in 1884-5, when out of about five hundred young 
trout only one had dropsy of the yelk sac, and theegg from which it had been 
hatched had been kept in brackish water in order to ascertain whether that 
would preclude its hatching. 
On November 11, 1884, about 12,000 eggs of Lochleven trout were milted from 
a salmon smolt a year older than in the last experiment. About 9,500 hatched on 
January 28, but many died of dropsy of the sac; and on June 19 about 5,000 
healthy young ones were turned into a rearing pond. Dropsy in this experiment 
did not set in quite so rapidly or severely, neither were so many proportionately 
affected. In this instance, again, there was evidently deficiency of vitality, 
probably due to the age of one of the parents, and if so that must have been 
the male, which was forty-three months old. 
Several other experiments were made, but with similar results, which would 
seem to demonstrate that a sickly or feeble offspring results from crossing young 
salmon, as par or smolts, with mature trout, no matter how vigorous tke latter may 
be. As a corroboration of this opinion the following experiment, also made at 
Howietoun, may be quoted. November 14, 1884, about 500 eggs, each having a 
diameter of 0°17 of an inch, were taken from a Lochleven trout not quite two 
years old. These were fertilised from another of the same race, but older. But 
only about a dozen hatched on January 28, 1885, and of these seven lived and were 
turned out into one of the rearing ponds. This is a very instructive experiment, as 
not merely demonstrating the small size of the eggs given by young mothers, but 
likewise as pointing out that such as are obtained from young parents either hatch 
indifferently or even fail to do so, simply due to deticiency of vitality on the 
mother’s side, This experiment must likewise cause one to hesitate before expect- 
ing the eggs of two-year-old hybrids to be good hatchers, another season at least 
being necessary in order to arrive at satisfactory deductions on this head. 
Intercrossings have likewise been carried on at Howietoun between trout and 
char. On November 15, 1882, about 2,000 eggs of the Lochleven trout were 
fertilised from the milt of the American char (Salmo fontinalis). About one in six 
failed to hatch, while monstrosities were numerous among the progeny. Some 
were blind with one or both eyes, others had bull-dog malformations of the snout, 
