124 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



degree for very short periods in our warmer and more pro- 

 tected coastal waters. 



Turning now to the question of efficacy, we meet with this 

 difficulty — Mr. Fryer apparently does not accept the turning 

 out of millions of healthy young fry into the sea as a proof 

 of successful hatching operations. He seems to demand 

 a demonstration that the number of adult fish in the neigh- 

 bourhood has increased, without taking into account the 

 fishing operations that may be going on. In asking for 

 immediate proof that the fry live to become adult fish the 

 opponents of fish hatching are taking up what may seem 

 a very secure, but is, I consider, a very unreasonable position. 

 So many factors enter into the case that it is almost impos- 

 sible to devise a crucial experiment, or give immediate 

 scientific proof of a result. The demand may possibly be 

 satisfied in any locality next year, or the answer may be 

 delayed for 10 years or for longer ; and yet the fisheries may 

 all the time be largely benefitted by — may owe their con- 

 tinued existence to — the artificially hatched fry added to 

 the population of the sea. And this may be the case even 

 if not a single individual out of the millions of fry set free 

 ever lives to become adult. 



I do not think it at all probable that such unfavour- 

 able conditions ever exist, but I wish to point out that 

 even in such an extreme case the expenditure on land 

 and the sacrifice of life of the fry in the sea will not 

 have been in vain. If we try to realise the struggle 

 for existence in the sea, the toll that is taken at every 

 period of life from the egg to the adult, but which is excep- 

 tionally heavy in young stages, a moment's reflection will 

 show that the addition in any natural hatching area of 

 some millions of young fish must distribute the danger of 

 being caught by an enemy over a much larger number 

 of individuals and so give to each a greater chance of 



