<) 



tlie ectodcnii, and, sluiuld futuic invc^stio-atioiis })r()vo 

 siicli to 1)0 the case, the Xemeiteans wcnihl present the 

 interesting feature of possessing- an endoderm which pro- 

 hahly does not contrihnte to the digestive jnices, hnt is 

 only concerned Avith absoipiioii. Jkit in the absence of 

 decisive embryological data, and of the histological 

 appearance of the varions parts of the lining of the 

 alimentary canal after injection of various sul)stances, 

 nutritious or otherwise, the qnestiini must be left open. 



The oeso23hagus is constricted at its jiosteiior end, and 

 behind this constriction starts the intestine, with its 

 lateral pouches, where the character of the lining of the 

 alimentary canal becomes entirely changed. The intes- 

 tinal cells are laige, though long and nariow (PI. HI., 

 rig. 2). ]*]acli contains a somewhat (dongated nucleus near 

 its base, whilst between it and the ciliated surface are a 

 number of small round bodies which shew neither nucleus 

 nor anv definite stiiu'luit'. These little bodies have been 

 considered to be stored food material absorbed in this 

 region, and in some* Xemerteans several types have been 

 distinguished. 



The region of the regularly airanged intestinal diver- 

 ticula (PI. TIL, tigs, (i, and 7, /.d.) continues 

 almost to the anus where the alimentary canal opens to 

 the exterior bv a veiv short rectum. It is worthy 

 of note that traces of food are rarely found in 

 the digestive canal of a Xemertean. Yet various 

 anecdotes illustrating their vcnacity have been given, 

 among which may be mentioned an observation of 

 *l{iches, who, writing about Mirrura pui'ijurea, states that 

 " A specimen of about ■! or 4 cm. was placed in a dish with 



* Rifhos. T. ir. A list of the Nemertines of Plymouth Sound. Journ. 

 >hu-ine Biol. Assoc. Vol. III. 



