'!9i5 J Recent Literature. 245 



the two races appearing under these names in the A. O. U. list are united, 

 while two races of islandus are recognized from Greenland. 



The use of Colymbus for the Loons and (Enanthe for the Wheatear is 

 correct as already stated in these columns and must be followed by the 

 A. O. U. Committee. 



It is matter for general congratulation that three Committees, working 

 independently, have been able to come to such close agreement on all mat- 

 ters covered by the International Code of Nomenclature, and the differ- 

 ences that still remain emphasize the fact that it is no longer questions of 

 nomenclature but of taxonomy that cause diversity in names. 



The Committee of the B. O. U. deserve to be congratulated upon the 

 excellent piece of work that they have accomplished and, with the exception 

 of the unfortunate thirteen nomina conservanda, we can heartily recommend 

 the nomenclature of the new list to all who write on British birds. — W. S. 



Hankin on Animal Flight. 1 — No ornithological problem has caused 

 so much speculation, even from the earliest times, as the soaring bird; 

 to quote Sir Guilford Molesworth, although " many theories have been 

 advanced .... they have all been miserably insufficient"; while even Lord 

 Kelvin admits: "That which puzzled Solomon puzzles me also." Practi- 

 cally everyone who has written on the matter has had a theory and the 

 literature of the subject as a whole may be said to consist of a maximum 

 of explanation with a minimum of observation. It is therefore a gratifica- 

 tion to find a work that is almost exclusively devoted to observation, such 

 as Dr. Hankin has produced, — observations moreover of the most detailed 

 and careful kind which constitute one of the most valuable contributions 

 to the subject of flight which has ever appeared. 



The need of such a record of observation is recognized by the author who 

 says by way of introduction: " Those best qualified to form an opinion 

 have as a rule had little or no opportunity of studying the facts at first 

 hand. Such authorities have, in some cases, published accounts of soaring 

 flight which have consisted entirely of explanation. Others have related 

 a few facts with more or less tentative explanations. The present book 

 will be found to contain the facts of the case with no explanation at all." 



Dr. Hankin's observations were carried on mainly at Agra, India, where 

 the opportunities for the study of soaring flight — always best seen in the 

 tropics — were excellent. His records show that there is a definite time 

 each day when soaring becomes possible, which is earlier as the season 

 advances. The presence of either wind or sunshine is an absolute necessity 



i Animal Flight. | A Record of Observation^ By | E. H. Hankin, M. A., Sc.D. | 

 Late Fellow of St. John's College, Cambridge, | Honorary Fellow of Allahard 

 University, | Chemical Examiner and Bacteriologist to | the Government of the 

 United Provinces | and of the Central Provinces, India, Associate Fellow of the 

 Aeronautical Society of | Great Britain. | (First Edition) | London: | Iliffe & 

 Sons Ltd., 20, Tudor Street, E. C. | [1913?] 8vo. pp. 1-405 + Index unpaged. 

 Price, 12s. 6d. 



