1919-] Letters, Extracts, and Notes. 367 



of gleaning furtliev information that I ask for notes on the 

 following, where any observations have been made: — 



1. Date and place of observation. 



2. Species or type of bird. 



3. Direction of flight. 



4. Altitude of flight. 



5. Ground velocity of flight, 



6. Direction of wind and weather conditions. 



7. Whether single birds, a small or large flock, or 



numerous small flocks were observed. 



Many officers of the R.A.F. possess such material, and 

 w'e want to get it while it is still fresh in their memory, 

 though I quite realize that many officers who have done a 

 large amount of flying may never have seen birds much 

 above the level of the earth. In my own experience of 

 some hundred hours in the air in East Africa, Palestine, 

 and France I have only on three occasions seen birds, 

 though 1 secretly regarded their observation of more 

 importance than the real object of my flight. 



It is in the hope of persuading officers of the R.x\.F. to 

 contril)ute their notes to science, and that in future thev 

 may record any observations in these columns, that I write 

 this letter. 



Youi's very truly, 

 British Delegatiou, K. Meinertzhagex. 



Paris. 

 ■26 February, 1919. 



The Names of the Soug-Thrush and the Redwing. 



Dear Sir, — Among all changes of names which have 

 been made in accordance with a stricter application of the 

 law of priority, there can hardly be any which has [)rovoked 

 more displeasure and dissension than the alteration of the 

 names of the birds mentioned above, and probably this 

 difference in opinion may still last a very long time. The 

 cause of this is, of course, that Linnaeus had thoroughly 

 mixed up the two species. In Syst. Nat. ed. 10, 1758, 



