208 TAPEWORMS OF HARES AND RABBITS— STILES. 



The division of the genus Twnia. — In connection with the citations, 

 1>. 162, from Meyner's work, 1 take this occasion to rei)ly to his remarks 

 regarding the eftbrts whicli \l. Bhmchard, Eailliet, llassall, and I have 

 recently made to bring some order into the genus Tamia. Upon page 

 8 of his thesis he says: 



Die Versmbe von Hlaiu^hard, Stiles und Raillict die Uebersichtlichkeit der 

 Fainilio tier Tioniaden duicli Zcrlegmig in eine Auzahl von Uuterfamilien zii erlcitb- 

 tern, siud niclit ala besonders gliicklicho zn bezcichnen, nanu-ntlicli mit liiicksiclit 

 darauf, dass die, von verscbiedeuen (iesicbtspunkten aiisj^ebende, stets nur an einer 

 bt'scbriinkten Auzabl von S])e(ies vorgonoiumenc Eintbeilnng notbgedriingen ancb 

 zn verscliiedencn Resnltaten fiibren inusste. Be.vor niclit durcb eingeliende For- 

 scbnngen wenigstens die typischen Ilaiiptfonnen als feststclieud augeseben wer- 

 denkunncn, diirfteu derartige Expcriniente wobl nicht auf allgemoine Anerkennnng 

 zn recbnen liaben, bis dabin aber verl'eblen sie gauz entscbieden ibren eigentlicbeu 

 Zweck, niimlicb Klarbeit nnd Eiufacbbeit iu die Systeuiatik zu briugen. 



In writing this critique, which is of course welcomed both l)y my 

 Frencli colleagues Blanchard and liailliot, and by Hassall and myself as 

 showing the view which Dr. Meyner takes of our work, the author has 

 unfortunately overlooked several very important points. First of all, 

 he has overlooked that veiy important princii)le so well expressed by 

 Bacon in the words, "Truth emerges sooner from error than from con- 

 fusion." ^oiie of us look upon our efforts to classify these jiarasites as 

 perfect, free from criticism, avid flnal beyond revision. But errors 

 which we may have connnitted in these attempts to aid in reducing 

 the chaos which exists in the genus Tania can be corrected very easily. 

 We have the satisfaction of knowing that our work has been adopted 

 by a number of specialists in helminthology and hardly feel called u[)on 

 to apologize for the attempts we have made, even if not approved of by 

 Veterinarian IMeyner. 



A second error Dr. Meyner has fallen into is that he has forgotten 

 that every classification must undergo an evolution (with epigenesis !). 



He would evidently have us include all four-suckered tapeworms in 

 the heterogeneous and collective genus Twnui, "until at least thety[)ical 

 chief-forms can be looked upon as established," although he failed to 

 give an explanation of what he meant by ''the typical chief-forms." If 

 he refers to the type species of genera, he has lost sight of the fact that 

 the tyi)e species of a genus is designated by any given author, and can 

 not be changed after once being so designated. The type species is, 

 therefore, optional, subject of course to certain principles, in the case 

 of the author who designates it and obligatory iu the case of other 

 authors. I'ossibly Meyner refers to the most highly specialized species 

 in the different grou[)s. If so, however, his advice to wait until we 

 study u]) such forms and decide which are the most highly specialized 

 is wanting in reason. It is certainly far better to create a new genus 

 for a form when we can not logically unite it with the kuown genera, 

 than it is to place it with forms with which it does not agree in any 

 important character. 



