THE NATURAL GROUPING OF THE 



(BOMBIML) WITH SPECIAL REFERENCE 

 TO BIOLOGICAL CHARACTERS. 1 



O. E. PLATH, 

 DEPARTMENT OF BIOLOGY, BOSTON UNIVERSITY. 



In the introductory pages of his rather negativistic treatise 

 on the psychobiology of bumblebees, Wagner ('06), after calling 

 attention to the immense taxonomic importance of biological 

 characters in the case of spiders, cites by way of contrast- 

 several examples of the disconcerting polymorphism in the color- 

 ation and habits of bumblebees and comes to the following pessi- 

 mistic conclusion : 2 ' These are the facts which compel us from 

 the very beginning to give up all hope of finding fixed and un- 

 alterable characters in the taxonomy of bumblebees for the 

 elucidation of the biology of these insects, and vice versa, of deriv- 

 ing suitable data from their biology for taxonomic purposes." 



As we shall see later, this statement of Wagner ('06), as so 

 many other of his assertions (cf. von Buttel-Reepen, '07, '14; 

 Wheeler, '19; and Plath, '236, '24), is based upon superficial 

 observations and is wholly untenable. During the past fifty 

 years, several important attempts, most of which antedate 

 Wagner's ('06) work, have been made to subdivide the Bremidre 

 into natural groups. These subdivisions have been based either 

 upon (i) coloration, (2) structure, or (3) habits, and in some cases 

 on two or all three of these. 



In this paper the writer wishes to discuss in detail those 

 attempts to subdivide the Bremidae into natural groups which 

 have been based primarily upon biological characters, and to sub- 



1 Contributions from the Entomological Laboratory of the Bussey Institution, 

 Harvard University, No. 247. 



"Dies sind die Tatsachen, welche uns von allem Anfange an zwingen, jede 

 Hoffnung darauf aufzugeben, in der Systematik der Hummeln feste und unverander- 

 liche Ziige fur die Aufklarung der Biologic dieser Insekten zu finden und umge- 

 kehrt aus dem biologischen Kriterium geeignete Angaben fur die Systematik der 

 selben . . . zu schopfen." 



394 



