THE CANADIAN ENTOMOLOGIST 287 



primitive representatives of the Apterygota have, so that a study 

 of the "Myriopoda" in question is fully as important for a phylo- 

 genetic study of insectan evolution, as that of the above-mentioned 

 Crustacea. 



Any attempt to derive winged insects from forms unlike the 

 apterygotan type of insect is wholly unwarranted, to my mind, 

 since the loudest winged insects, such as the ephemerids, Plecoptera, 

 etc., are anatomically strikingly similar to such Apterygota as 

 the Lepismids, etc., which in turn are connected by intermediate 

 forms with the lowest Apterygota such as the Protura: and no one 

 who has carefully examined the Protura could doubt that in 

 them we have the most primitive known representatives of the 

 insectan group; so that the recent attempts to derive winged 

 insects directly from a trilobite type of arthropod (without re- 

 ference to the Apterygota) are extremely "far fetched," to say the 

 least, and even the weight of Handlirsch's authority as a palae- 

 ontologist is insufficient to convince a skeptical morphologist, 

 when the evidence of anatomy is directly against Handlirsch's 

 assumption — although many recent writers who have not taken 

 the trouble to investigate the merits of the case, have unhesi- 

 tatingly accepted Handlirsch's astonishing proposal that winged 

 insects are to be derived directly from a trilobite type of arthropod 

 without reference to the Apterygota, and regardless of the facts 

 indicated by a comparative anatomical and embryological study 

 of apterygotan and pter>'gotan insects. 



Even if one were to grant, for the sake of argument, that the 

 anatomically and embryologically far more primitive Apterygota 

 are not so near the ancestral type of insect as the Pterygota are, 

 we would not be justified in assuming that the Pterygota are to 

 be derived from a trilobitan type of arthropod, since, as I hope 

 to bring out in a more detailed discussion of the question, the 

 Trilobita are more closely related to the Merostomata than to any 

 other arthropods (save perhaps the Apodidae), and serve to con- 

 nect the Apodidae with the Merostomata in a line of development 

 leading away from that of insects and toward the arachnid line of 

 evolution, instead of the trilobites standing more nearly in the 

 direct line of descent of the insectan type of arthropod. Insects 



