318 PROCEEDINGS OF THE ACADEMY OF [May, 



the constancy or lack of constancy of characters determining the 

 rank. This method, though requiring a zoological map for the 

 identification of some individuals, seems the most satisfactory way 

 to deal with such cases, where most of the examples from a given 

 area clearly fall into a given subspecies, comparatively few failing 

 to conform; but where mere average characters are used for the 

 separation of such forms, and especially where abnormal specimens 

 are selected and named, it is surely objectionable unless some term 

 is used to indicate a rank lower than subspecies. Professor Cockerell 

 some time ago 2 suggested the use of the term "mutation" to designate 

 sporadic variations from modification of the germ-plasm, "form" 

 for variations resulting from the immediate effect of environment 

 upon the individual, and "variety" for all other variations of lower 

 rank than subspecies. Such use of the terms "mutant" and "form" 

 would imply much greater knowledge of causes of variation than we 

 usually possess. It involves too much guessing as to the cause of a 

 particular variation in a particular case, and in most cases it is 

 impracticable to solve the problem by careful experimentation; 

 indeed, sometimes perhaps impossible. On the other hand, the 

 term "variety" is very confusing because it is so variously used. 

 As is pointed out in the article just refrered to, well-known naturalists 

 use it as an exact synonym of "subspecies" and also as a synonym 

 of "form" and "mutant." This was true of Hemphill and Binney, 

 but we should have progressed since their time. Some forms desig- 

 nated varieties by those gentlemen are so distinct that nowadays no 

 naturalist would hesitate to give them full specific rank. On the 

 other hand, however, Hemphill in several cases selected abnormal 

 specimens from a colony and gave them several varietal names, 

 and was not always even consistent in the use of such names in 

 sorting his material for distribution. Had he made it clear in just 

 what instances his varieties were so selected, and in what cases they 

 were really from quite distinct colonies and fairly represented the 

 colonies, it would be easier for us now. If, for example, his oquir- 

 rhensis and gabbiana were from separate colonies as indicated by his 

 notes and partially confirmed by our material, most of the material 

 from one colony conforming to one type and most of it from the 

 other colony conforming to the other type, we should be justified 

 in con?idering them two subspecies, notwithstanding intergrading 

 examples in either colony. In some cases we can only determine the 



"-Nautilus, XX, 58-60. 



