A discussion of certain questions of nomenclature, as applied to parasites. Iß7 



eilt Status of science, and not by the condition of the 

 subject at the time the diagnosis was written or the 

 species or genus iudicated. 



In the first place one must determine what characters are valid 

 in recognizing a genus or species by its definition or indication. In 

 refereuce to this poiut, I take the stand that any remark, reference, 

 or indication which enables a specialist in the group in ques- 

 t i n to recoguize with reasonable certainty what form is referred to, 

 is a valid character and must be admitted, especially when 

 judging the work of earlier authors. If, for instance, an 

 earlier author proposed the name X y for "a worm about 3 feet 

 long in the kidney of a dog", we may conclude with reasonable cer- 

 tainty that he referred to the female Dioctophyme renale^ and we 

 should hence recognize the name X y, although not a Single anatomical 

 character except length is given. Should it afterwards develop that 

 two or twenty species, from the modern Standpoint, had been included 

 in this supposed Single species, I should still feel it obligatory (ceteris 

 paribus) upon me to retain X y for one of these forms. 



Further, the truth must not be overlooked that a definition or 

 indication which may perhaps not be recognizable to-day, may at some 

 future date be perfectly clear, or at least it may be clear that the 

 author used the name for such and such forms, which to-day are 

 cousidered to belong to x different genera and y ditferent species. 

 Accordiugly, we may refuse to recognize a name to-day, but may be 

 compelled to give it recognitiou to-morrow. Hence in studying the 

 nomenclature of earlier authors we should consider their definitions 

 and indications in the light of the science, not only of to-day but also 

 of the time when the articles were published. Any other position 

 than this would necessitate our ignoring thousands of names proposed 

 during the early part of this Century, and would equally necessitate 

 that the authors of next Century should ignore thousands of names 

 published during the past fifty years, names which can equally well 

 be retained. 



To make my position clear : I believe in retaining an early name, 

 whenever wecan find a reasonable excuse for doing so, 

 since the older the name, the better. See, below, for instance, the 

 genus Sphaerostoma. In this connection, it should be recalled that 

 the earlier date we can give to a name the more secure it is from 

 later rejection on account of the Rule of Homonyms, or from other 

 cause. A generic name dated 1800 or 1850 Stands a much greater 



