208 TAPEWOEMS OF HAKES AND RABBITS STILES. 



The division of the genus Tcenia. In connection with the citations, 

 p. 162, from Meyner's work, I take this occasion to reply to his remarks 

 regarding the efforts which E. Blancliarcl, Eailliet, Hassall, and I have 

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

 8 of his thesis he says : 



Die Versucbe von Blauchard, Stiles und Railliet die Uebersichtlichkeit de'r 

 Familio der Tamiaden durcli Zerlegung in eine Auzahl von Unterfainilien zu erleieb- 

 tern, siud uiclit als besonders gliicklicbe zu bezeicbiien, namentlicb mit Riicksicbt 

 darauf, dass die, von verscbiedeuen Gesicbtspunkten ausgehende, stets nur an einer 

 bescbrankten Anzabl von Species vorgenonimene Eintbeilung notbgedrungeu aucb 

 zu verscbiedenen Resultaten fiibreu musste. Bevor nicbt durcb eiugebende For- 

 schungen wenigstens die typiscben Hanptforinen als feststebend angeseben wer- 

 deu koimeri, diirften derartige Experimeute wobl uicbt auf allgemeine Anerkennung 

 zu recbnen baben, bis dabiu aber verfeblen sie ganz entscbiedeu ibren eigentlichen 

 Zweck, niimlicb Klarbeit nnd Eiufacbbeit in die Systematik zu briugen. 



In writing this critique, which is of course welcomed both by my 

 French colleagues Blanchard and Eailliet, 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 very important principle so well expressed by 

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

 fusion." iNone of us look upon our efforts to classify these parasites as 

 perfect, free from criticism, and final beyond revision. But errors 

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

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

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

 by a number of specialists in helmiuthology and hardly feel called upon 

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

 Veterinarian Meyner. 



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 Tcenia, "until at least the typical 

 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 type 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 in the case of other 

 authors. Possibly Meyner refers to the most highly specialized species 

 in the different groups. If so, however, his advice to wait until we 

 study up 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 known genera, 

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

 important character. 



