178 HINTS ON THE ANCESTRY OF INSECTS. 



the still lower maggot-like forms. While on the one hand Cam- 

 podea, with its abdominal feet, and the larva of Lithobius are 

 related, so on the other the Lepisniatidfe, which are very near 

 the Blattariaj, are nearly related to the Myriopods, since their 

 abdominal segments often bear appendages (Machilis). The 

 Campodea-form appears in most of the Pseudoneuroptera [Libtl- 

 lulids, Ephemerids, Perlids, Psocids and Termes], Orthoptera, 

 Coleoptera, Neuroptera, perhaps modified in the Strepsiptera 

 [Stylops and Xenos] and Coccidai in their fii'st stage of devel- 

 op^ieut, and indeed in many of these at their first moult." 

 Farther on he says, "A larger part of the most highly developed 

 insects assume another larva-foi'm, which appears not only as a 

 later acquisition, through accommodation with certain definite 

 relations, but also arises as such before our eyes. The larvas of 

 butterflies and moths, of saw flies and Panorpa3,show 

 the form most distinctly, and I call this the caterpillar 

 form (Raupenform). That this is not the primitive 

 form, but one later acquired, we see in the beetles. 

 The larvoe of Meloe and Sitaris in their fully grown 

 condition possess the caterpillar form, but the new- 

 born larvas of these genera show the Campodea form. 

 The last form is lost as soon as* the larva begins its 

 parasitic mode of life. * * * ^he larger part of the 

 beetles, the Neuroptera in part, the bees and flies 

 (the last with the most degraded maggot form) pos- 

 sess larvjE of this second form." He considers that 

 204. Tipula the caterpillar form is a degraded Campodea form, the 

 Larva, result of its stationary life in plants or in wood. 

 For reasons which we will not pause here to discuss, we have 

 always regarded the cruciform type of larva as the highest. 

 That it is the result of degradation from the Leptus or Cam- 

 podea form, we should be unwilling to admit, though the mag- 

 gots of flies have perhaps retrograded from such forms as the 

 larvae of the mosquitoes and crane flies (Tipulids, Fig. 204). 



That the cylindrical form of the bee grub and caterpillar is 

 the result of modification through descent is evident in the cat- 

 erpillar-like form of the immature Caddis fly (PI. 3, fig. 2). Here 

 the fundamental characters of the larva are those of the Corj'- 

 dalus and Sialis and Panorpa, types of closely allied groups. 

 The features that remind us of caterpillars are superadded, 

 .evidently the result of the peculiar tube- inhabiting habits of 



