218 MICHIGAN ACADEMY OF SCIENCE. 



other groups of animals, the confusion of special geographical position 

 with essential morphological character leads, and always will lead, to 

 most erroneous conclusions concerning the distribution and history of 

 species. A well known American mammalogist is said to hold the view 

 that any mammal resident on an island must necessarily be a different 

 sub-species from the form on the neighboring mainland, because of its 

 isolation. If such views are current among systematists, (which I greatly 

 doubt), it is not strange that morphologists, physiologists and embryolo- 

 gists have long held systematic zoology in contempt, and even now regard 

 with suspicion our claims to a place among the real devotees of science. 



4. Characters which will not distinguish corresponding ages or sexes 

 of tico forms ought not to he made the hasis of a new name. 



This seems so self-evident, I hesitate to state it but as it may prove 

 the one on which we can all agree I mention it, although it is no more 

 obvious to me than principles one and three. Of course this does not 

 mean that the characters must be present in both sexes at all ages. On 

 the contrary, the characters may be present only in one sex or at a par- 

 ticular time of life, but they must distinguish from the corresponding- 

 sex or age. 



5. Characters ichich are notoriously variahle in a gwen group ought 

 not, within tliat group, to he made the hasis of a neio name. 



As an example of what is meant by this principle, the common star- 

 fishes (Asterias forhesi and vulgaris) of the New England coast may be 

 cited. Their color is so remarkablv variable that it would be follv to 

 form subspecies based upon the color alone. 



6. Characters ivhich may he fairly interpreted either as individual 

 peculiarities or as dichromatic diversity, ought not to he made the hasi^ 

 of a neiv name. 



If this principle were honestly followed many new species and sub- 

 species would be cancelled, and it would lead to much greater caution in 

 basing new names upon single individuals. 



The above six principles are suggested, not with any idea that they 

 will meet with universal approval, but in tlie hope that they may precipi- 

 tate a. discussion which will lead to definite results. At some not far- 

 distant day let us trust, the charge of basing new names upon "dis- 

 tinctions without a difference" will be one that cannot be brought legiti- 

 mately against American zoologists. 



