376 EXAMINATION OF THE PRESENT STATE 
The presence of active ova appears to be a sure sign that 
maturity is approaching, and, in most cases, that the fish will spawn 
at the next spawning season, Mr. Cunningham, however, thinks it 
possible that the yolk appears rather earlier in the sole than in 
other flat-fish which he has studied, so that more than a year may 
elapse between the first appearance of the active ova and the first 
spawning of the fish. I do not think that this interferes with the 
value of the distinction for macroscopic purposes, since the first 
appearance of yolk globules is apparent only under the microscope, 
and I have only observed active ova, with the naked eye, in young 
soles which might from their size be reasonably expected to spawn 
during the same year. 
In any case the presence of active ova is an infallible sign of 
approaching maturity, and the further stages of maturation are so 
obvious as to call for no remark. But when the fish has become 
fully ripe and has discharged its spawn, the question arises as to how 
we are to distinguish the empty shotten roe from one which has never 
developed eggs at all. As a matter of fact the question can usually 
be settled, in flat-fish, even at a very considerable interval after 
spawning has taken place, by the presence of more or fewer ripe 
eges which have somehow failed to be excluded. ‘These remain 
either in the cavity of the ovary or in its duct, and gradually 
decompose there, but the shells remain recognisable for a long period. 
But without this certain proof of previous spawning, there are 
characters which appear to me to be in themselves a_ sufficient 
distinction. The really immature roe is short, plump, and very 
firmly fixed between the body-wall and the spines (hemal) below 
the backbone, while in a fish which shows evidence of having spawned 
I have always found the roe wide and flaccid in front, and 
nearly always extending further backwards along the spines than in 
the case of an immature roe. It is also comparatively loosely 
lodged in the position which it occupies. Indeed, if the specimen is 
fresh, a groove which can be felt by passing the finger along the 
skin over the roe is almost a sufficient test of the shotten condition, 
but in a stale fish the groove is more or less perceptible even if the 
specimen is quite immature. 
A recently shotten ovary usually contains a certain number of 
small active ova, which, as Cunningham holds, are probably absorbed 
and do not form part of the next season’s crop. Then succeeds, in 
some species at all events, a condition in which all the living ova 
are in the inactive condition, but no instance has been recorded in 
which the shotten condition could not be proved by the presence of 
dead eges or by other features associated with this condition. 
Cunningham makes the pertinent inquiry : ‘ are there cases in which, 
