208 BRITISH BIRDS. 



to the south of Italy and to Tunis. This is less satisfactory 

 than the conclusion reached with regard to the Crows : the 

 records along these routes are few and far between, and do 

 not, in our opinion, justify any more definite statement than 

 that the Rossitten Gulls spread over Europe in southerly, 

 westerly, and intervening directions from that place, tending, 

 of course, to be found in the neighbourhood of the sea or of 

 large rivers and lakes. Some better proof of the existence 

 of such routes as are described- is wanting. Time and further 

 returns will ceitainly clear up this point, but in the meantime 

 too much stress should not be laid on such hypothetical 

 conclusions. Theorising at too early a stage of such an 

 enquiry is to be condemned as likely to prejudice the final 

 results. The report is an important addition to the literature 

 of bird-migration. 



A. L. T. 



