66 PROC. ENT. SOC. WASH., VOL. 24, NO. 2, MAR., 1922 



I would especially emphasize the fact that a preliminary study 

 of crustacean anatomy is indispensible to the proper under- 

 standing of insectan anatomy, since the parts of a crustacean 

 (unlike those of a chilopod) are for the most part built upon 

 exactly the same plan as those of an insect, but have remained 

 in a condition much nearer the ancestral one; and by comparing 

 the parts in a series of Crustacea, we can trace the development 

 of the various modifications back to their very source, thereby 

 revealing the true nature of the various parts in a way that is 

 not. even approached, for completeness, by any other group of 

 arthropods. The chilopods, on the other hand, present practi- 

 cally no structures built upon exactly the same plan as in insects, 

 but are modified along their own special paths of development, 

 so that it would be impossible to derive the parts of an insect 

 in general, from the types of structures present in any known 

 chilopod. The truth of this statement is so readily apparent 

 if one will only take the trouble to make even the most super- 

 ficial comparison of the parts of one of our common and easily 

 obtained chilopods (which are to be found under dead logs in 

 any wood) with those of a common mayfly nymph, Machilis, or 

 any similar primitive insect, that it is hardly in keeping with 

 the modern spirit of scientific truth to continue to foist upon 

 unsuspecting and inexperienced students the fallacious and 

 easily refuted hypothesis that insects are descended from chilo- 

 pods! 



Current Misconceptions. 



One of the prevalent misconceptions concerning the nature 

 of the maxillae of insects, is the view that they represent the 

 second maxillae of Crustacea, instead of the first maxillae of 

 Crustacea, with which they are really homologous. This 

 practically universally accepted view apparently owes its 

 origin to the erroneous claim of Hansen,- 1893, and Folsom, 

 1900, who maintain that the so-called "superlinguae" of insects 

 are homologous with the maxillulae or first maxillae of Crus- 

 tacea; and since they mistake the "superlinguae" of insects for 

 the first maxillae of Crustacea, they naturally mistake the first 

 maxillae of insects for the second maxillae of Crustacea. The 

 only semblance of proof brought forth in defense of the view 

 that the "superlinguae" represent the maxillulae (first maxil- 

 lae) of Crustacea is Folsom's description of an alleged super- 

 lingual segment in an embryo of Anurida^ which he claims is 

 the representative of the first maxillary segment of Crustacea; 

 and those unfamilar with the embryology of insects in general 

 (in which no superlingual segment has ever been found) or with 

 the embryology and anatomy of Crustacea, have been com- 

 pletely deceived by Folsom's much-heralded "discovery." 

 In his extensive and extremely thorough study of apterygotan 



