1919-] Geographical Distrihution and Migration. 383 



In writings on the birds collected in a certain area we 

 freqnently see a great amount of detailed description of the 

 birds collected, their wing-measurements, etc., and, except 

 for the number of specimens obtained and their sexes, no 

 further detail. A rough guess can be made at the date of 

 collection from the time of year during which the collection 

 was made, but this even is often impossible. There is rarely 

 any indication as to whether the species was common or 

 whether the specimens collected were the only ones observed, 

 whether the bird was resident, on passage, or in winter- 

 quarters. Again, how frequently the major value of a paper 

 is lost by failure to grasp the importance of assigning sub- 

 specific value to those specimens which represent geographical 

 races. The occurrence of the Song-Thrush in Portugal is of 

 little value without knowledge as to whether the bird is of 

 the British or Continental race; or, again, the passage of the 

 Redstart in Egypt or Palestine loses its importance without 

 a determination of its subspecific rank, which alone helps us 

 in studying the bird's distribution and migration. 



It is perhaps ungenerous thus to criticise the great efforts 

 made by Field and Museum Naturalists, but the writer 

 himself being an offender in this respect, reference is made 

 to this most important point in the hopes of stimulating 

 further effort to gain the maximum results from the 

 slaughter of such beautiful creatures as birds, to enable us 

 to interpret correctly the many and varied facts with which 

 Nature presents us, and to solve the complex problems of 

 distribution and migration. No killing of birds can be justi- 

 fied merely to compile a list of species obtained in a certain 

 locality. Careful field-notes by the collector and an accurate 

 determination of subspecific rank (where this exists) by the 

 man who works out the collection can alone justify its 

 formation. A mere list of birds likely to be found in 

 almost any part of the world could be compiled by any 

 studious ornithologist in the library of the Zoological Society 

 in Regent's Park, without a visit to the locality in question 

 and without taking the life of a single bird. 



Neither are we dealing with a science which is stationary. 



