Evolution 



As to the origin of the Enteropneusta, opinions are somewhat 

 divided. Their blood system and their development would seem 

 to suggest a descent from the ringed worms. On the other hand, 

 their possession of a snout, and their very slight indication of 

 division into segments, would seem to separate them from the 

 group mentioned and to connect them rather with the Nemertines. 

 The latter view is perhaps the more probable. 



78 



