JAMES NE WTON BASKE TT. 93 



Towhees well justify the tendency of Prof. Baird and others 

 to assign distinct generic names to each group. The re- 

 semblance between the eggs of some Wrens and some 

 Thrashers is more striking than the external resemblances 

 between the birds. 



It is not claimed, however, that any of this testimony is 

 more than collateral or slightly confirmatory, nor that defi- 

 nite diagnoses can be based on egg-resemblances ; but that 

 the many complex sources from which some of our groups 

 have sprung, can in many instances — sometimes in the 

 clutch of an individual — be perceived in the eggs ; that 

 great variations in markings, shape, texture, and tint, often 

 indicate either or both a variety of kinships or a multiplicity 

 of routes up through which either the bird or the egg has 

 come. The subject is full of uncertainties and difficulties, 

 because of the extent of these relationships and their con- 

 sequent intricacies. From the standpoint of the bird alone 

 our avifauna is a stock of remnants, a chain with many 

 " missing links," a series of survivals full of reversions as 

 well as developments ; so that it is doubtful if any scale can 

 ever be drawn that will represent true relationships. The 

 writer undertook one once for a class before which he was 

 lecturing ; but he was younger then than he is now. By 

 taking the morphology of any group of organs the thing 

 may be approximated ; but on that line only, for a high de- 

 velopment of one organ does not imply a high development 

 of others. So when the sternum leads one way, the vomer 

 another, the feet a third, the beak a fourth, the pattern of 

 the feathering a fifth, and altricial and precocial relations a 

 sixth, with naked or downy young when hatched hinting a 

 seventh, leg-muscles an eighth, toe-tendons a ninth, and all 

 the shaping of parts by adaptation and its concomitants, the 

 tendencies of habit and inheritance, hint others ad infinitum, 

 the way is far from clear ; and if oology can shed the faintest 

 glimmer upon the dim trail it should not be despised. 



Dependent on some of these, independent of others, and 



