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any special importance to it, we choose the last species left in simply 

 because it is the only one left to us. 



As a matter of fact, the groups are in themselves often of no 

 systematic importance whatever. — But we have to use names, we 

 agree that the old ones will answer the purpose very well ; and all we 

 want to do is to definitely fix some single species on to each name 

 so that we shall know what we are talking about when we use these 

 names. 



We have to clear our minds of "Bogies"; and simply adopt some 

 method which our present immediate necessities suggest and the past 

 action of systematists renders possible. 



If Dr. Dahl cannot discriminate between the two processes, and 

 holds that consistency in applying rule (A) in the matter of "names" 

 involves a fundamental logical inconsistency when we apply rule (B) 

 in the case of "types", one can only suggest that we do not move on 

 the same intellectual plane. 



Definition of "Type". 



Dr. Dahl has made a great discovery — "For Mr. Cambridge 

 the sole aim of a type is to make the subdivision ofa group 

 very easy for an Author". If by this he means that for me the 

 object of a type is that we may more readily classify under recognised 

 names the material which comes before us, well and good. Inciden- 

 tally of course subdivision may become less difficult when one has 

 the generic characters made definite and distinct; just as the identifi- 

 cation of new species is rendered more easy by the publication of 

 excellent tables and figures. But what does Dr. Dahl suppose the 

 object of systematic zoology to be ? to assist the student who wishes 

 to classify his material, or to throw dust in his eyes and effectually 

 prevent him from making head or tail of the matter? There are I 

 believe systematists who avoid giving the only characters which are 

 of any value in separating species, in order to choke off other workers 

 from the study. This at least is the only interpretation one can put 

 upon the phenomenon of the utterly inadequate diagnoses of genera 

 and species which appear. But as far as I am myself concerned I at 

 least endeavour, however unsuccessfully, to make the classification 

 clear and distinct. If this action makes it easier for other authors to 

 make new genera and species, that is an incidental result; but not the 

 main object held in view when one desipes definite types — we do not 

 care whether it is easy or difficult for authors to subdivide genera; 

 what we do want is that the characters of the genera and species 

 already founded shall be as clear as possible. 



31* 



