Portrait of Santa Cruz Island Jay, Aphelocoma insularis 

 By W. Leon Dawson 



species, and especially, its adaptability to changing environment. Such an appraisal 

 presupposes a considerable knowledge of taxonomic relationships, or more exactly, of 

 phylogeny; and it is, in short, a sort of epitome of racial history from the value 

 standpoint. More particularly, then, the task of genology, or geno-dynamics, is to 

 estimate the relative value of a species, and to express that value in terms of energy 

 and achievement, noting in each case, direction of development, rate of developmental 

 progress, degree of success or failure, mobility, adaptability, and the like. 



Without presuming to answer all the questions raised by this hurried definition 

 of a science (the discussion of whose set terms I shall now dismiss), I wish to point 

 out some "geno-dynamic" values which are indicated by a comparison of the eggs of 

 Aphelocoma californica (Vigors) and Aphelocoma insularis Henshaw. Whether or 

 not one follows a recent authority (Oberholser) in recombining the western mainland 

 jays of the Aphelocoma type, californica, woodhousei. and the like, as one species, it is 

 enough for our purpose to note the existence in California of a mainland Aphelocoma 

 jay, A. californica, only slightly, if at all, differentiated by somatic characters (sub- 

 species immanis claimed by Grinnell and oocleptica by Swarth). We note further that 

 this substantially uniform species is characterized, apparently throughout its range, by 

 a high degree of variation in respect to its eggs This variation is so great that it has 

 given rise to two well-recognized types, the "red'' and the "green," with every com- 

 bination or intergradation between these extremes. It is not necessary "for our 

 purposes to describe these variations minutely, but the reader is referred for illustra- 

 tion to the colored frontispiece in this number. So far as ascertained, this variation, 

 however derived, observes the well-known Mendelian laws, and the strains thus indi- 

 cated exist quite independently of local or environmental conditions. Whatever else 

 this set of facts may mean, it probably indicates an active, mobile, virile, or dominant, 

 type of bird. The recurrence of eggs, for example, of the "red" type in widely 

 sundered localities does not indicate the presence of a "race" of jays of wide distribu- 

 tion and still imperfectly amalgamated with a hypothetical race laying green eggs. 'It 

 denotes rather the ancient and long established presence of a certain tendency to 

 vary inherent in the reproductive stream, transmissible both in general and in par- 

 ticular by heredity (i. e., breeding true to type), but existing in utter independence of 

 somatic change (i. e., variation in the individual bird, the individual being the contem- 



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