THE ATLANTIC SLOPE NATURALIST. 41 



jay, a magpie, a nutcracker, and perhaps in a starling, an oriole and so on, 

 but we must not run into the danger of carrying this theory of presumption too 

 far. That is a very common danger, and one that in times past lias led some 

 anatomists into the deepest pitfalls of error. In the example given, or exam- 

 ples rather, taken as a whole, the summation of the knowledge of the nestling 

 of the crow at all of its stages constitutes a very good peg to hang other mor- 

 phological facts upon, as they refer to closely allied species, but as I have just 

 intimated, the capacity of the aforesaid peg must not be overcrowded. If this 

 is done disaster will follow, and suspicion be cast, sooner or later upon some of 

 the statements hung upon it that never had a right to be supseuded there in 

 the first place. The natural classification — that is the real relationships ex- 

 isting among the immense number of representatives of the class birds since 

 they first became more or' less completely differentiated from the rep- 

 tiles up to include the world's existing ornis — a classification we all hope to be 

 unanimous about some day — would be that part of the science of ornithology 

 that would suffer, indeed be the chief sufferer, from such unsubstantiated deduc- 

 tions. That young crows are black like their parents when they quit the nest 

 and that the nestlings at a similar time in the case of many species of jays also 

 have a plumage more or less like the old birds is no reason that such will be 

 found to be the case throughout the family Corvidce although it may be but 

 these very ''may be's" and "presumably so's" are the very class of dangers 

 to which I refer. That a young crow is black when it quits the nest is no 

 reason why a young oriole in its first feather plumage should resemble either 

 of its parents simply for the reason that the Corvidae and the Icteridae are re- 

 lated families. In my time, I have known, however, anatomists, or those 

 who considered themselves to be anatomists to jump at conclusions in their 

 own special fields of labor quite as hazardous as this. 



What has been said in the last paragraph or two, brings me directly up to 

 the next uoint to be considered, and that is this — our work throughout must be 

 made comparative to be of value or to fulfill its greatest use and highest pur- 

 pose — namely, to meet the ends of taxonomy, classification. 



Series of facts, or even single facts, must be compared and intercompared, 

 and contrasted, within the limits of known affinities and within the range of 

 more or less near relatioushius. A structure by structure comparison, during 

 the various stages of its growth, in the case of the skull of a humming bird 

 and that of a greoe would furnish us with a kind of knowledge that, taxonom- 

 ically speaking, would be of but little service to us, but if we compare all that 

 we know of the developmental anatomy of the skull of a grebe, with that of a 

 loon, structure by structure, and change by change, and all this knowledge 

 with the corresponding information as derived from our researches upon the 

 skulls of young representatives of the Alcae, and their known allies, then the 

 real needs of classification are met, and the safe substantial progress of this 

 most important department of the science of ornithology is served. 



Scattered throughout anatomical and ornithological literature in different 

 parts of the world w T e maec with some contributions to the subject we are con- 

 sidering in the present article, but they are scarce in comparison with what 

 has been done along other lines in those two departments of learning. Taking 

 the question of the plumages of nestling birds alone as they appear at different 

 stages, it is truly wonderful to note how very little is said upon this subject of 

 the various modern ornithological "Keys"' and " Manuals. ' ' The works in 

 Ridgway and of Goues. are good examples of this. Any number of birds have 

 been slighted in this particular by both of these authors. Coiv j s, for example, 



