315 
of the innumerable drift nets stopped all the large salmon, but 
let all the small ones through. The eggs when taken proved 
to be at least one-third smaller than those of most previous 
years, and the average number of eggs to the fish was about 
3,500, against 4,200 in the previous year.” 
Subsequently (1880) Dr Guyrner observed, in the “ Intro- 
duction to the Study of Fishes,” that “the ova of teleostean 
fishes are extremely variable in size, quite independently of the 
size of the parent species. The ova of large and small indi- 
viduals of the same species, of course, do not differ in size.” 
(Page 159). Livrvesron Srons, in the “ Bulletin of the United 
States Fish Commission,” 1882, vol. ii., page 11, observed, 
respecting the eggs of the Salmo fontinalis, that those taken 
from the larger breeds are fully twice the size of those given 
by such as reside in mountain rivulets. From this period 
several observers have noticed that the eggs of Salmonoids 
undoubtedly differ in size consequent on certain physical causes, 
consequently the author who would characterise a species by 
the size of the eggs, would possibly be merely adding another 
synonym to the confusion previously existing. A certain excuse 
may be offered that prior to the formation of the Howietoun 
fishery either very little or no pains had been taken to segre- 
gate the fish of different ages, consequently means were not 
available for solving the question. I now propose to give the 
size of the eggs of these fishes as observed during November 
this year, premising that besides measuring individual eggs, 
care was taken to measure six, eight, or ten in a row, and take 
the mean as the average size. 
Salmon eggs were from 0-20 to 0°30 of an inch in diameter ; 
from smolts or grilse raised in the Howietoun ponds, from 0-20 
to 0°22 inch; from a small sea trout, 0°175 to 0°18 inch. Loch 
Leven trout, at eight years old, 0-20 to 0-24 inch; at seven 
years old, 0°19 inch; at six years old, 0:185 to 0°19 inch; at 
two or three years old, 0-17 inch; thus clearly showing that 
the average diameter of trout eggs increases with the age of 
the parent at least up to the eighth year. The American char, 
S. fontinalis, at two year old, 0°13 to 0°14 inch; at three year 
