THE CANADIAN ENTOMOLOGIST. 



CAN THE DIPTERA BE CONSIDERED THE HIGHEST 



INSECTS? 



BY C. H. TYLER TOWENSEND. 



In the Nov., 1892, number of the Canadian Entomologist, pp. 

 269-70, there is printed a paper which was read by Professor H. Osborn 

 before the Entomological Club of the A. A. A. S. at its Rochester meeting 

 in August, 1892. It is entitled: "Honey-bee or House-fly." In this 

 article Professor Osborn questions the view, first advanced by Hyatt and 

 Arms, that the Diptera are to be considered the highest insects. At the 

 end of the paper appear the following remarks, which were made at the 

 time the paper was read before the meeting : — 



" Mr. Smith thought that the line of argument adopted by Messrs. 

 Aldrich and Townsend was inconclusive, and that the article referred to 

 carried with it its own refutation. He thought Mr. Osborn was correct in 

 that the orders should be placed parallel, but that groups or families were 

 more highly developed in some orders than in others. Mere specialization 

 is never a test of rank in itself, and any line of argument that places the 

 Hippoboscidse at the head of the insects as the highest in rank is simply 

 unworthy of attention, since it omits the intellectual or nervous develop- 

 ment as a factor." 



The over-confident and assuring manner in which the above paragraph 

 disposes of the subject is rather ludicrous. One might fancy the question 

 finally answered, and consigned to oblivion. I feel safe in saying that 

 such a hasty and incompetent dismissal of the subject will command little 

 attention from anyone who is well informed in insect embryology. 



Professor Osborn's paper simply makes the point that there are objec- 

 tions to attempting an expression of lineal rank or descent in groups of 

 animals, but that the orders of insects are divergent, or more or less 

 parallel developments from a common form. 



The writer, in his note on the subject in Science (June, 1892), did not 

 attempt to express the idea that the orders of insects led up in a natural 

 or any other series to the Diptera ; nor is any such view held by Hyatt 

 and Arms, or Professor Aldrich, in what they have written on the subject. 

 I desire to say also that I have not in any way upheld the view that the 

 Hippoboscidae should be considered the culminating point, but have 

 rather pointed to the cyclorrhaphous families as occupying that position. 



It is very conclusively shown by Hyatt and Arms, Insecta, pp. 273-4, 



