122 GENERAL ORNITHOLOGY part ii 



technical name for constant use. That name is compounded of its 

 genus, species, and variety. No infallible rule can be laid down for 

 determining what shall be held to be a species, what a conspecies, 

 subspecies, or variety. It is a matter of tact and experience, like 

 the appreciation of the value of any other group in zoology. There 

 is, however, a convention upon the subject, which the present 

 workers in ornithology in America find available ; and there is no 

 better rule to go by. They treat as " specific " any form, however 

 little different from the next, that is not known or believed to inter- 

 grade with that next one ; between which and the next one no 

 intermediate equivocal specimens are forthcoming, and none, con- 

 sequently, are supposed to exist. This is to imply that the differen- 

 tiation is accomplished, the links are lost, and the characters actually 

 become " specific." They treat as " varietal " of each other any 

 forms, however different in their extreme manifestation, which they 

 know to intergrade, having the intermediate specimens before them, 

 or which they believe with any good reason do intergrade. If the 

 links still exist, the differentiation is still incomplete, and the 

 characters are not specific, but only varietal, in the literal sense of 

 these terms. In the latter case, the oldest name is retained as the 

 specific one, and to it is appended the varietal designation : as, 

 Tufdus migraforius propinquus. The specific and subspecific words 

 are preferably written with a small initial letter, even when derived 

 from the name of a person or place, after the example of Dr. P. L. 

 Sclater and other eminent British naturalists. 



One other term than those just considered sometimes forms part 

 of a bird's scientific name : this is the subgenus. When introduced, 

 it always follows the generic term, in parentheses ; thus, Turdus 

 (Merula) iorquafus. This is cumbrous, especially when there are 

 already three terms, and is little used. I have latterly discarded it 

 altogether. There is no difference in kind between a subgenus and 

 a genus, — it is a difference of slight degree merely ; and modern 

 genera have so multiplied that one can easily find a single name for 

 any generic refinement he may wish to indulge. 



It has always been customary to write after the bird's name the 

 name of the original describer of the species, — originally and 

 properly, as the authority or voucher for the validity of the species 

 named. But as genera multiplied, it was often found necessary to 

 change the generic name, the species being placed in another genus 

 than that to which its original namer referred it. The name of the 

 person who originated the new combination came to be generally 

 suffixed, presumably as the authority for the validity of the classi- 

 fication implied. As this was to ignore the proprietorship of the 

 original describer, it became customary to retain that describer's 

 name in parentheses and add that of the classifier ; thus, Turdus 



