136 



COMPARATIVE ANATOMY 



CHAP. 



side, and this ganglion becomes the infpaintestinal gang-lion. The 

 pleurovisceral connectives, in which these ganglia lie, now cross and 

 give rise to the condition called ehiastoneupy. The visceral 



wlct 



Pios. 113, 114, 116, 110.— Diagrams to illustrate the sUtting forward of the palUal complex 

 along the right side of the body and the development of ohiastoneury. jj. Mouth ; nk, vlpl, 

 iilp, original left cerebral-, pleural-, and pedal-ganglion ; -ulpa, iirpu, original left and original right 

 parietal ganglion ; tda, original left auricle ; »os, nros, original left and original right osphradiuni ; 

 nht, iwcf, original left and original right ctenidium ; ml), base of the mantle ; mr, edge of the .same ; 

 >ii, mantle cavity ; v, visceral ganglion ; ve, ventricle ; a, anus. 



ganglion in which these connectives terminate posteriorly lies as 

 before under the intestine. 



It is unnecessary to show in detail how this displacement also affects 

 the heart and its auricles, the osphradia, and the nephridial apertures. 



