8 THE LIFE OF THE SALMON 
a strong argument in favour of allowing all smolts to 
get to the sea. It is much easier to accustom a young 
parr or a Loch Leven trout to salt water than to 
accustom a smolt to fresh water. 
It has to be noted, however, that the eggs of the 
fertile females of the Howietoun experiments were 
not fertilised by milt from male salmon reared 
under the same conditions, but by milt from Loch 
Leven trout. This materially detracts from the value 
of the result. Within recent years a limited number 
of the smolts reared in the Duke of Richmond and 
Gordon’s ponds at the mouth of the Spey were found 
to contain well-developed ova, and an experiment 
was made as to the possibility of rearing brood from 
smolt eggs. It has long been known that male parr 
or smolts are occasionally sexually mature. So far 
as I am aware, the occurrence of ripe female smolts 
amongst artificially reared and hand-fed salmon had 
not previously been noted. Aripe male smolt not being 
procurable when the ripe females were first found, 
fertilisation was satisfactorily accomplished by using 
milt trom an adult salmon. The fry hatched out and 
grew quite normally, and, as I was able to note from 
specimens kindly sent me by Mr. Rae, the superin- 
tendent of the Duke’s salmon fisheries, were at the 
age of one year quite indistinguishable from the 
salmon fry produced from the eggs of adult 
females. 
The following year, however, when ripe female 
smolts were again discovered, care was taken to 
obtain ripe male smolts for purposes of fertilisation. 
On this occasion, although at first impregnation 
