304 MR. H. H. STIRRUP ON 



wall. These are the muscles used when the pharynx is everted 

 and then withdrawn. There is another ingrowth of cells from 

 the ventral side, anterior to the pharyngeal ingrowth, but this is 

 much smaller (fig. 4). 



The (Esophagus gradually merges into the intestine; the actual 

 point where oesophagus ends and intestine begins cannot be 

 defined. 



The Intestine can be seen quite plainly owing to its darker 

 colour, due partly to the food in it and also to its external covering 

 of cells which contain many oil-globules. It is constantly under- 

 going peristaltic contractions, the waves running from behind 

 forwards. The intestine is covered over its whole length with 

 chloragogen-cells. When these cells break away from the gut- 

 wall, they are seen to be spherical, and contain numerous oil- 

 £,lobules of various sizes. The cells are about 16 ^ in diameter. 

 The intestine is internally strongly ciliated. Owing to the 

 chloragogen-cells which cover the gut, I have never been able to 

 see whether the ciliary current in the intestine begins at the anus 

 and runs forward, or whether it runs backwards to the anus. 

 Stephenson (17) has recently published some interesting con- 

 siderations on the phenomena of antiperistalsis and ascending 

 ciliary action in the intestine of aquatic Oligochsetes, He has 

 never observed ascending ciliary action from behind forwards in 

 the Enchytraeidse, but thinks that it is very possible that such an 

 action will be found to occur in this group. His reason for this 

 is that " the inhalent function of the intestine is common in the 

 aquatic Oligochseta, and is evidenced by a widely occurring 

 ascending ciliary current in the intestine" (17, p. 74). 



The problem of the nutrition of these Enchytrseids is highly 

 important. As already mentioned, I have seen Enchj'trseids 

 situated inside decaying leaves and literally eating their way 

 through the soft tissue of the leaf. When the contents of the 

 gut is examined, it is found to consist chiefly of disorganized 

 vegetable cells. These are usually brown and dead, but I recently 

 examined the contents of the gut of an Enchytrseid which had 

 been feeding on the green living cells of a plant. In this case 

 the contents of the gut was green in colour, and a greenish fluid 

 was also slowly oozing out from the anus whilst the worm 

 was under pressure. Green vegetable cells could be recognized, 

 although they were being gradually disorganized. These were 

 the soft parenchymatous cells of the leaf or stem. In contrast 

 with these cells, the long vessels and tracheides of the vascular 

 bundles wei-e always extruded quite whole and apparently little 

 changed. This would be due, no doubt, to their thick walls 

 resisting the action of the digestive juices. 



The epithelial cells of the gut are strongly ciliated (PI. XLVI, 

 figs. 4, 5). The nuclei of these cells stain deeply, and there are 

 present numerous large vacuoles or spaces, which often contain , 

 masses of material ; this material has no affinity for any stains, 

 but is almost colourless. They suggest to me that nutrition may 



