INTESTINAL RESPIRATION IN ANNELIDS. 741 



the other hand, it may be very obvious even with the low power, starting from the 

 anus even though the anus be closed at the time. It can be followed through about 

 the posterior ten segments of the body ; after this point the body of the animal may 

 become too opaque to allow of the phenomenon being observed further ; it probably, 

 however, extends to a considerably greater distance up the gut, since in one favourable 

 instance it was followed up through the last twenty segments. 



Antiperistalsis was noted in all the specimens observed. Its extent varies ; 

 beginning from the anus, it may be confined to a few of the most posterior segments ; 

 or it may extend for ten, thirteen, fifteen, or eighteen segments. 



Branchiura sowerhyi Bedd. 



I have recently had the opportunity of examining in the living condition several 

 specimens of this interesting worm, which I found near Lahore (•'^1). 



Antiperistalsis was present in all the specimens observed ; the character of the 

 contractions, however, varied somewhat. In the first specimen the contractions, 

 beginning at the anus, were regular, ample, and rapid ; the anus opened momentarily, 

 then closed, and the wave thereupon commenced, as if the animal were taking a 

 gulp of water and passing it upwards along the canal. The contractions did not 

 affect the middle region of the gut; but further forwards they were again visible, 

 though fitful and of small extent, embracing only a segment or two of the gut here 

 and there. 



In another specimen also, contractions were frequent and ample, the lumen of the 

 gut in the posterior part of the animal being occluded by the passage of the wave ; 

 particles were seen ascending the intestine. In one specimen it was noted that the 

 contractions were better marked in the anterior than in the posterior part of the 

 intestine. 



Reversed ciliary action was not observed ; but it may be allowable here to call 

 attention to the intake of water by the " gulping " action of the anus. The following 

 observation was made : — It was noted that the anus opened, and a gulp was taken ; the 

 anus closed, and the gulp was passed up the intestine by antiperistalsis ; this was 

 immediately repeated, and so on for a series of such gulps, after which the anus 

 remained closed, and the posterior part of the intestine was quiescent for a time ; then 

 more gulps were taken at irregular intervals. 



Enchytr^id^. 



I have examined in all a fair number of species of Enchytrseids ; the observations 

 were mostly made at Millport, while I was investigating the littoral Oligochseta of the 

 locality. All show a great uniformity, and it will not be necessary to describe each 

 species separately. 



