176 



TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



the label in use now was employed, that is, a button of vulcanite 

 above and below instead of the bone and brass discs. It has no 

 advantages over the old mark, and is more expensive. Details 

 of all these experiments, and of most of the fish recaptured, 

 have been given in various reports of the Lancashire Sea- 

 Fisheries Laboratory, but all the data are now summarised 

 for the first time and unnecessary detail is avoided. 



(1) The Liverpool Bay Experiments. 



It was soon noticed that the results of the experiments 

 repeated themselves from year to year. Therefore they are 

 all combined and are regarded as one. All the Junes are 

 thrown together, and the recaptures from these experiments 

 are all recorded in the same way. Then all the Julys are 

 combined, and the recaptures of plaice taken in July (in 

 general) are made to give us the migrations of the fish liberated 

 in June and July, and so on — the details will become easily 

 grasped by studying the charts given hereafter. The places 

 of recapture for any one month (which are rather approximate, 

 of course) are plotted on a chart and then a contour line is 

 drawn round about these positions. This method of treatment 

 was suggested to me long ago by J. 0. Borley, and it is a very 

 convenient one. 



Note, first, the sizes of the fish liberated and recaptured : — 



Mean 



Numbers 



Numbers 



Mean 



Numbers 



Numbers 



Lengths. 



Liberated. 



Reported. 



Lengths. 



Liberated. 



Reported. 



16-5 



4 







28-5 



17 



12 



17-5 



18 







29-5 



5 



14 



18-5 



31 



1 



30-5 



2 



7 



19-5 



89 



2 



31-5 







4 



20-5 



250 



12 



32-5 



3 



2 



21-5 



200 



32 



33-5 



1 



5 



22-5 



183 



39 



34-5 



1 



4 



23-5 



97 



39 



35-5 



1 



1 



24-5 



96 



33 



36-5 







1 



25-5 



47 



25 



37-5 







2 



26-5 



38 



24 



38-5 











27-5 



23 



21 



39-5 







1 











1,116 



281 



