156 



HINTS ON THR ANCESTRY OF INSECTS. 



The first to discuss this subject of the ancestry of insects was 

 Fritz Miiller, who in his "Fiir Darwin,"* published in ISOS, says, 

 at the end of his worli, "Having reached the Nauplius, the 

 extreme outpost of the class, retiring 

 farthest into the gray mist of primitive 

 time, we naturally look round us to see 

 whether ways may not be descried thence 

 towards other bordering regions. * * * 

 But I can see nothing certain. Even 

 towards the nearer provinces of the Myri- 

 opoda and Arachnida I can find no bridge. 

 For the Insecta alone, the development 

 of the Malacostraca [Crabs, Lobsters, 

 Shrimps, etc.] may perhaps present a 

 point of union. Like many Zoeae, the 

 Insecta possess three pairs of limbs 

 serving for the reception of nourishment, 

 and three pairs serving for locomotion ; 

 like the ZoeJB they have an abdomen 

 without appendages ; as in all Zoeae the 

 mandibles in Insecta are destitute of palpi. Certainly but little 

 in common, compared with the much which distinguishes these 

 two animal forms. Nevertheless, the supposition that the In- 

 secta had for their coramoil ancestor a Zoea which raised itself 

 into a life on land, may be recommended for further examina- 

 tion" (p. 140). 



Afterwards Hseckel in his "Generelle Morphologic" (18CG) 

 and "History of Creation," published in 1868, reiterates the 

 notion that the insects are derived from the larva (Zoea, Fig. 

 190) of the crabs, though he is doubtful whether they did not 

 originate directly from the worms. t 

 It may be said in Opposition to the view that the insects came 



190. Zoea, 



• Translated in 18G9 by Mr, Dallas under the title "Facts for Darwin." 

 fWhether that common stem-form of all the Tracheata [Insects, Myriopods and 

 Spiders] which I have called Protracheata in my 'General Morphology' has devel- 

 oped directly from the true Annelides (Coelelmin_thes),or, the next thing to this 

 {zunachsf), out of Zoea-form Crustacea (Zoepoda), will be hereafter established 

 only through a sufficient knowle<lge and comparison of the structure and mode of 

 growthofthe Tracheata, Crustacea and Annelides. In eitlier case is the root of the 

 ■ Tracheata, as also of the Crust.acea, to be sought In the group of the true jointed 

 worms {Annelides, Gephyrea and Rotatoria." He considers the first insect to have 

 appeared after the Silurian period, viz., in the Devonian. 



