Classijication of Birds. 105 



brate or invertebrate, the structural differences to be found 

 among the forms making up the natural minor groups of 

 existing birds are far less apparent than in any one of them. 

 Taken in their entireties, the difference between an Apterjx 

 and a Humming-bird morphologically is not to be compared 

 with what exists, when thus contrasted, between such forms, 

 for example, as a man and an Ornithorhynchus among 

 mammals, or between a Lancelet and a Bass among fishes. 

 Birds are an extremely compact group, and the disposition is 

 altogether too prevalent, in attempts to classify them, to accord 

 too high a rank to not a few of the divisions above the 

 family. Were birds fishes the entire congregation of them 

 would hardly make more than a respectable order. They 

 are a lucky lot of closely affined volant feathered reptiles 

 that have specifically multiplied at a wonderful rate since 

 they sprang into existence, and useful and charming as the 

 majority of them are in nature, their taxonomy nevertheless 

 has puzzled the wits of many a man since Aristotle lived, and 

 will doubtless continue to do so in the years to come. To 

 arrive at their true affinities and a natural grouping of the 

 class it will be necessary to utilize every fact that we possess 

 in regard to their biology ; by this it is meant every palajon- 

 tological fact, every fact referring to geographical distribution 

 for all time, every morphological fact, besides all that is 

 known of their biology, habits, and development. In so far 

 as their anatomy is concerned, some of the systems have un- 

 doubtedly proved to be of more value than others in the 

 matter of classification. For example, in this particuhir the 

 study of the skeleton teaches us more than a comparison of 

 the dermal appendages, but the osseous system is by no means 

 all-suflicient to meet the ends of taxonomy, as some still seem 

 to believe. With regard to this, it is easy to agree with what 

 Professor Alfred Newton has said, when commenting upon 

 the value of the work left us by Nitzsch, for " there can be no 

 part of a bird's organization that by proper study would not 

 help to supply some means of solving the great question of 

 its affinities. This seems to the present writer to be one of 

 the most certain general truths in zoology, and is probably 

 admitted in theory to be so by most zoologists, but their 

 practice is opposed to it j for, whatever group of animals be 

 studied, it is found that one set or another of characters is the 

 chief or favourite of the autliors consulted — each generally 

 taking a separate set, and that to the exclusion of all others, 

 instead of effecting a combination of all the sets and taking 

 the aggregate." Thus it is that, notwithstanding the relative 

 value of the characters furnished on the part of any particular 



