NORTH SEA INVESTIGATIONS. 99 
favorable, as the tub was small, and the water stagnant or only occa- 
sionally renewed. ‘The percentage of dead at the end of the hour 
varied. On one occasion 24 cod and 34 whiting, being the total 
catch of these species, were placed in the tub. At the end of 
an hour 21 cod and all the whiting were alive and vigorous, two 
cod were sickly, and one was dead. The haul on this occasion 
yielded the usual quantity of prawns, crabs, and lumps of Sabellaria, 
&c., and I believe the favorable result of the experiment was simply 
due to the small number of fish, the capacity of the tub being in- 
sufficient for the respiration of larger numbers. 
Another time the catch included 111 cod and 99 whiting, which 
were placed in the tub. At the end of an hour (an hour and a half 
before all were counted) the number of living was 99 cod and 63 
whiting. There was some delay in getting the fish into the tub, in 
which, moreover, they were very much crowded. I do not think 
that, when fish are returned to the river in the ordinary way, the 
mortality is ever greater than in this last experiment, and probably 
it is much less. Other experiments support the conclusion that 
the cod are more hardy than the whiting, and it was noticed that 
fish of both species, which appeared moribund when first placed 
in the water, gradually recovered and ultimately seemed none the 
worse, 
Of course the survival of a fish for an hour cannot be said to 
prove its absolute recovery, and I had no further means of testing it. 
The two miles’ jolting in a cart involved in conveying fish from the 
dock to the Cleethorpes tanks proved very fatal to the young cod 
and whiting, and few of the latter survived it for any length of time. 
They seemed to suffer much more than the cod from any injury to 
the skin, such as must necessarily occur from the rostra of the 
prawns in the net, as well as from handling. Nevertheless, my own 
opinion, based on the facts which I have recapitulated, is that a large 
proportion of these returned at once to thei natural surroundings 
escape any serious injury. 
Soles and lemon soles, of whatever size, are seldom injured by 
capture in the shrimp-trawl. Lemon soles are especially hardy. A 
large number of those which were caught by the “ Vallota” were 
placed in the Cleethorpes tanks. There was slight mortality 
amongst them for the first few days, probably more due to the 
journey than to any other cause, but the bulk of them, five months 
later, are still alive and apparently in excellent health. Soles which 
had been chafed, either in the net or in handling, ultimately died 
in the tanks, as at Plymouth (teste Mr. J. T. Cunningham, The 
Common Sole) ; but I do not think it follows that they die if returned 
to the sea, as soles which have evidently recovered from rather serious 
