: 73 
THE FECUNDITY OF THE PLAICE. 
By R. D. Laurie. 
It may be useful to put on record two estimations 
of the number of ova produced by a plaice, which I made 
at Prof. Herdman’s suggestion while working, during 
last aster vacation, at the Port Erin Biological 
Station. The determinations were made by Dr. Fulton’s 
method,” in which a fractional portion of the roe (or 
ovary) of the fish is weighed and the ova are counted, and 
from the numbers so obtained, and the total weight of the 
two ovaries, the total number of ova present is calculated. 
No determinations of this kind have hitherto been made 
from the fish in the Irish Sea. 
The fishes dealt with were two ripe mature females, 
which died in the tanks at Port Krin during April, 1905. 
The data are as follows :— 
Total length | Total weight Total weight of 
(in centimetres). | (in grammes). | both ovaries. 
1 | 49 (193 inches) 1,346 | 3155 
y 52 (204 inches) 1,318 bet i Ges 
Small portions of the ovarian substance, weighing LO 
grains each, were taken from various parts of the 
organ, and the ova were counted. The results of these 
counts are given in the following table :— 
* Oth An. Report Fish. Bd. for Scotland. Pt. III., pp. 243-268. 
