SOCIETY OF NORTHERN ILLINOIS. 203 



oiilv instance the one of Colaptes Iii/hridiis. so named from the sup- 

 position of its bein^ a cross between ijo\a\Aef> aurafus and Mcricanus. 

 treated at hiri^e by Dr. Corns in his Handbook of Northwestern Or- 

 nithob)<;y, ])a^es 2V)8-2U4. Tlie <jjoklen-wini)jed woodpecker (auratiis) 

 has its l>ri^]it veHow repbued by oraii«i:e-red in Mr.ilcdnns. and the 

 snp])<)sed lujhridns seems a connecting link, partaking of the charac- 

 teristics of each. Dr. Corns saysi ''Dr. Haydens numerous exam- 

 ples are principally those that enal)led I'rof. Baird to elucidate one 

 of the most remarkable cases in Americ;in ornithology the ])orfeet 

 intergradation of two such distinct sj)ecies as (nn-(it/()< and Mr.rica- 

 nus. This author adopted, without qualification, the hypothesis of 

 hybridization, remarking, in proposing the name hi/hrifhis. ' By the 

 above name I intend to cover a remarkable series of woodpeckers 

 from the Upper Missouri ami Yellowstone. coml)ining the character- 

 istics of Colapfes anratus and Mexican us, in })roportions varying 

 with almost each individual, and leading irresistibly to the conclusion 

 that thev are the descendants of originals of the s])ecies mentioned 

 above, mixed up l)y interbreeding of successive generations, to a de- 

 gree unp.iralleled in the annals of ornithology." Dr. Conis adds: 

 '' If there ever were a case of hylu'idization to an unlimited extent, 

 resulting in fertile offspring that again and again interbred, this 

 would ai)pear to be one: and it has been so acce|)ted by orithologists 

 without hesitation." \^\\i he proceeds to question the soundness of 

 the theory, and mentions a statement of Mr. Allen, that Floridan 

 exani])les of (\ auratiix sometimes show red touches in the black 

 maxillary i)atches: and of Mr. J. H. Batty, who tells of a New Jer- 

 sey s]jecimen got a few years since, with mixed red and black cheek 

 ))atches. from which he concludes that these variations cannot be due 

 to hybridization, as the C Mr.riauiiis is never found in the neighbor- 

 hood of New Jersey or Florida. 



This discussion is interesting and important as showing how the 

 dilferent s])ecies may a])])ro;ich each other in characteristics by natu- 

 ral pi-ocess of evolution, and yet the changes and variatit)ns fail of 

 forming a fixed type. It also tends to show some of the difficulties 

 in the way of identification of individuals that vary from the recog- 

 nized characteristifs of their species. Some years ago the tendency 

 was towards making the most of these variations in the way of new 

 varieties and even new species. Later discoveries, coupled with more 

 careful examinations, have reduced several of these supjiosed new 

 varieties and species to individual variations from the usual tyjie of 

 well known species, while in two or three instances two supposed 

 distinct species proved to be but nnile ami female of the same s])ecies. 



The design of classification is. of course, to aid in identifying 

 s))ecies of individuals. If confined within ])ro])er limits it is not only 

 an aid, but a necessary one. ibit when it is reduced to the shading 

 of pin feathers, in order thereby to subdivide and multiply species. 

 we submit that it tends onlv to confusion worse confounded. To 



