228 



MYRIOPODA. 



at the expense of the yolk now accumulated in the enteron, this 

 growth in length proceeding as before, by the formation of new 

 segments from the still undifferentiated caudal lobe (rf. Figs. 112- 

 115). The antennae are now distinctly segmented (Fig. 115, at), 

 and the mouth-parts are approaching the adult form, but the other 

 limbs are still simple and truncated. At a stage somewhat later 

 than that depicted in Fig. 115, when the embryo has thrown off 

 the provisional cuticle, Metschnikoff observed the first movements, 

 which consisted of slow extension and flexion of the body. 

 Metschnikoff points out that, in these movements, the extremities 

 might better be compared with the ventral cirri of many Annelids 

 than with the rapidly moving limbs of the Myriopoda. 



rd "mro 



Fio. 115.— Embryo of Geophihis after the splitting of the egg-shell (eh). The ventral curva- 

 ture is still retained (after Metschnikoff). a, anus ; at, antenna ; d, yolk ; ch, egg-shell ; 

 ez, egg-tooth on the second maxilla ; g, brain ; miu, mouth-parts ; p, legs ; si, caudal lobe ; 

 vd, stomodaeum. 



Throughout the course of development that we have followed, the 

 body of the embryo has been cylindrical, and it retains this shape 

 for a time after it has hatched. It thus resembles in form a 

 Diplopod, until the dorso-ventral flattening of the body character- 

 istic of the Chilopoda takes place. At the stage of hatching, when 

 the " larval integument " is cast, Geophilus is said to possess all its 

 limbs, although these are still truncated (Fig. 115) and do not 

 enable it to move with freedom. The young Chilopod probably 

 passes through several moults before attaining the complete form 

 and size of the mother, although when hatched it bears a strong 



