Recent Literature. 



T05 



In a few instances Mr. Sharpe admits subspecies, as under Troglodytes 

 domestica, where parkmant, aztecits, and insularts are thus treated, but 

 such cases are exceptional ; the local races of Thryotkorus ludovicianus 

 and T. beivtckt are each accorded full specific rank, although spoken of as 

 " forms " of the species to which they are referred as races bj American 

 writers. His criterion for subspecies is therefore, to.saj the least, obscure. 

 Harforhynckus rufus longirostris is not only raised to the rank of a 

 species, but is separated from rufus by two intervening species, and is not 

 even spoken of as having a near relationship to H. rufus. Finally on this 

 point it may be sufficient to state that in the "subfamilies" Troglodytince 

 and Mimince no subspecies are admitted outside of the genus Troglodytes., 

 with the single exception of a West Indian form of Mimus. As in foi-raer 

 volumes, there is, as a rule, no direct comparison between closely allied 

 species further than that very inadequately furnished by the " key" to the 

 species standing at the head of each genus. We note a few changes of 

 names, among them Campylorkynckus couesi for what has commonly been 

 called C. brunneicaptllus, the latter name belonging properly to C. affinis 

 auct., for which it is here substituted. 



In respect to the classification followed in these volumes, Mr. Sharpe 

 states that it is based on that of the late Professor Sundevall. While he 

 adopts his higher divisions ("cohorts") of the Passeres, the arrangement 

 of the lesser groups bears little resemblance to the confessedly artificial 

 arrangement devised by Sundevall. While in the main Mr. Sharpe brings 

 the minor groups into more natural relationship, his relegation of the 

 Dippers (family CinclidcB auct.) to the position of a genus in the subfam- 

 ily of Wrens is, to say the least, novel if not unwarranted, while the 

 PtilorhynckiiKB and some other groups find themselves among decidedly 

 new associates. 



The preface to volume VI (dated December, 18S1) states: "It is hoped 

 that the succeeding volume (which will conclude the TimeliidcB, and which 

 has made considerable progress) will appear within the space of a twelve- 

 month, as also that, with additional extraneous help, the work generally 

 will make more rapid progress than has hitherto been possible." That 

 such will be the case is earnestly to be hoped, so great is the value of the 

 work to all general students of ornithology. — J. A. A. 



Birds and Insects.* — Our best authority upon the insect food of birds 

 has continued his observations upon the subject. Professor Forbes set 

 himself to answer the three following questions : i. Do birds originate 

 any oscillations among the species of insects upon which they feed } 2. Do 

 they prevent or restrain any oscillations of insects now noxious, or capa- 

 ble of becoming so if permitted to increase^ more^ freely.'' 3. Do they do 

 anything to reduce existing oscillations of injurious insects.? 4. Do they 

 sometimes vary their food habits so far as to neglect their more usual food 



* The Regulative Action of Birds upon Insect Oscillations. By S. A. Forbes. Bull. 

 No. 6, Illinois State Laboratory of Nat. Hist., Dec. 1882, pp. 1-31. 



