316 
old, 0°17 inch; at four years old, 0°18 inch. <A hybrid char 
being a cross between the British and American forms, the 
diameter of the eggs, at nearly two years of age, was 0.13 of 
an inch. 
DO LARGER EGGS PRODUCE SUPERIOR OFFSPRING ? 
The next question is whether there is any difference in the 
size of the eggs in two parents which are of: the same age and 
kept under the same conditions? In two Loch Leven trout, 
each six year old, a difference did exist, the diameter of the 
eggs in one being 0°19 of an inch, and in the other 0°18 of an 
inch. And that such might occur would even theoretically 
appear highly probable; for, as I have remarked, Livineston 
Srone observed that where food existed to a minimum amount 
the eggs were small; in fact, a deficiency of nutrition may 
occasion diminution in the magnitude of the ova. Also the 
size of the parent ought possibly to be likewise taken into 
account, for disease, crowding them when young, or other 
causes, may dwarf fish, and such a one would doubtless furnish 
comparatively small eggs. Can we detect any variation in the 
size of the eggs from a single parent? In this I exclude 
abnormal or diseased eggs, and still find that a variation in 
size does occur among the eggs from one fish. Such in 1854 
was pointed out by Ranson as observable among the eggs of the 
stickleback. I had eighty eggs of a Loch Leven trout 
spawned direct into a glass tube containing water, wherein 
they were kept for a week, the water being changed daily, and 
they became more distended than when first taken. Seventy- 
five were 0.25 of an inch in diameter, three were 0°20 of an 
inch, one was 0°175 of an inch, and one 0°15 of an inch. In 
looking through a large number of eggs of Salmonide, it 
seemed that from four to five per cent. are mostly smaller than 
the average size. Irrespective of the foregoing proving that 
the size of the eggs varies with the age and condition of the 
parent in the Loch Leven trout, I should mention that along 
with augmented sizes of the ovum is an increased thickness of 
the shell, a rather important subject for the fish culturist, 
a Fe i i i i i 
wegum 
