^"Is^ 111 ] Recent Literature. 65 



which members of the A. O. U. and other readers of 'The Auk ' will be 

 sure to recognize — a statement of habitat, and a technical description of 

 the plumage for the sexes, ages, and seasons. There is much to recom- 

 mend this simple treatment ; for the sportsman who already knows his 

 bird, or perhaps does not like technical caviar in his usual rations, can 

 decline this dessert, and take his main course of biography in straight* 

 easv reading. He will find these articles reasonably full, interesting as 

 well as instructive, and may feel confident of their high degree of reliabil- 

 ity; for Mr. Elliot has been out among the 'mud-dwellers' with his gun 

 himself, and what he knows of their ways smells less of midnight oil than 

 of gunpowder. 



The author's admirable treatment of the Phalaropes raises a point on 

 which we wish to remark. lie adopts three genera — ■ Crymophilus, Phala- 

 ropus, and Stegaiiopits. Contrary to the opinion of some of his contem- 

 poraries, chiefly younger than himself, the present reviewer knows that 

 recognition of genera in zoology is a purely arbitrary convention, mainly 

 to facilitate list-making. We can take what grade of differentiation we 

 please as our generic standard; but having adopted any one such, we are 

 logically hound by it, and must not read off with a fine vernier-scale in 

 some instances, and with a coarser gradation in some other cases. The 

 differences between the three species of Phalaropes are coordinated; any 

 one of them differs from the other two to the same degree that these do 

 from each other. There is then one genus, or else there are three 

 genera as Mr. Elliot rightly holds; there cannot be two genera. The 

 hitch in this case seems to have been, that the A. O. U. committee per- 

 mitted themselves to be influenced by a bit of faddism on the part of some 

 person to whom birds' beaks looked big and their toes small — one who 

 could see minute rostral modifications in a great white light, which so 

 dazzled him that he was blinded to equal or even greater differentiations 

 of digital structure. The same one-eyedness reduced the four-toed genus 

 Squatarola to a subgenus of Charadrius, yet left the three-toed genus 

 Arenaria (or Calidris) in full tig apart from Tringa (type canutus). 

 Now if we remember anything about a group of birds which engaged 

 our virgin pen about thirty-five years ago, there are no two genera of 

 Sandpipers so nearly indistinguishable in form as those represented by 

 Arenaria calidris and Tringa canutus, if we do not count their digits. 

 Why then do we discriminate these generically, yet fail to separate Squata- 

 rola helvetica by the same token from the species of Charadrius proper? 

 In point of fact, the evolutionary processes which result in the develop- 

 ment of an articulated digit -and its accessories, however small and 

 practically functionless it may be, or those which end in the suppression 

 of such a digit, are vastly greater in duration and in force than those 

 which merely modify the size and shape of a bill to some appreciable 

 extent; so that in ignoring the former to insist upon the latter, we have 

 probably travestied an evolutionary record of geologic date. 



But such points as these are niceties which need not have heen made in 



