and Growth-rate of the Lesser Sand- Eel. 283 
which are so largely in excess of mine in length, are accounted 
for by the fact that there were included in the bottles a 
number of larval herrings, which he appears to have measured 
and added to his list of sand-eels ; and these, although recently 
hatched, are much longer than the older sand-eels occurring 
with them. Apart from the more attenuated form, the 
presence in some of the yolk-sac, the difference in pigmenta- 
tion and in the position of the arms, are points which at once 
distinguish the two forms. 
In my last paper upon the plaice* I dealt with a fish 
whose spawning-period is accurately known within fairly 
narrow limits, and therefore the base-line or starting-point of 
any growth-curve is also known. In this case, on the con- 
trary, there is a good deal of doubt concerning the spawning- 
period, and it is hoped with this series to form a growth- 
curve which may help to the determination of this difficult 
point. At the risk of redundancy it is well to recapitulate 
the views held by various observers. 
Couch ¢ describes in accurate and detailed language the 
spawning process of the sand-eel, and as the result of his 
observations gives the shortest days of the year as the 
spawning-period on the south coast. 
Thompson corroborates this observation, but also gives 
July as the spawning month in Ireland. Day finds the 
ovaries advanced in August and September, and M‘Intosh § 
finds the same condition in May and June. Fulton § states 
that ripe specimens are caught in the end of June at Dunbar. 
Fullarton {| describes having met with spawning females in 
July. 
These divergent opinions by various observers can only be 
reconciled in one way, namely, by assuming that the lesser 
sand-eel has two spawning-periods, more or less confluent. 
It will be seen that the summer spawning-habit is proved by 
the observations of Thompson, M‘Intosh, Fulton, and Fullar- 
ton; whilst the winter is proved by Couch and Thompson, 
and possibly by Day. ‘The herring, whose larval form 
resembles the sand-eel closely in habits and general features, 
is known to have two spawning-periods, and we shall see 
below that on no other assumption can the facts with which 
we have to deal be explained. In Table I. are placed all the 
* “On Rate of Growth of the Plaice,” Thirteenth Annual Scott. 
Fishery Board Report. 
+ ‘Fishes of the British Islands,’ vol. 111. 
{ ‘ British Fishes,’ vol. i. 
§ ‘Ninth Scott. Fishery Board Report.’ 
\| ‘Twelfth Scott. Fishery Board Report. 
