CHAPTER XXVI 



THE SPARROW-LIKE BIRDS 



(Order Passeriformes) 



|E have now come to the last, but by no means the least, of the twenty- 

 one orders into which birds are here divided, for within its limits are 

 included approximately seven thousand species and subspecies, or 

 nearly half of all known birds. To give these the general designation 

 of Sparrow-like birds implies a more or less close resemblance to a typical 

 Sparrow, but as a matter of fact only a comparatively few would probably be 

 so recognized by the casual observer, and it is to be understood as standing, in 

 the absence of a better popular term, for the general passerine type, the actual 

 resemblance between them being often confined to agreement in minute, though 

 relatively important, anatomical characters. 



The difficulties of satisfactorily dividing and arranging this vast assemblage 

 are well set forth by Mr. Robert Ridgway, who says: " Notwithstanding this 

 enormous number of specific forms, the type of structure is remarkably uni- 

 form, and the group far more homogeneous than the lower groups of equal 

 rank. Consequently, subdivision of the Passeriformes becomes a matter of 

 extreme difficulty, and no arrangement has thus far been proposed which can 

 be considered entirely satisfactory. Indeed, it seems impossible to subdivide 

 the order, beyond a very limited extent, into lesser groups, which are equivalent 

 in taxonomic rank to the families of other orders, and the extent to which this 

 may be done is a matter concerning which systematists differ widely in their 

 views. ... It may be, and doubtless is, perfectly true that no more than 

 three passeriform groups can be defined which will be equal in taxonomic rank 

 to the families of other orders of birds; but the objection to this meager allow- 

 ance and it is a very serious one is that two of the three groups contain 

 together only about one fifth the total number of the species, so that there are 

 still left about five thousand species in the third. Obviously, these five thou- 

 sand species (more or less) must be susceptible of segregation into a consider- 

 able number of more or less trenchant groups; and there being so few grades 

 of rank between a family and a genus, what to call these groups becomes a very 

 serious question." 



As a provisional expedient, largely in the interest of convenience and pend- 

 ing fuller knowledge, Mr. Ridgway proposes to designate the ''families" of 



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