v HABITS FOOD REGENERATION I I 5 



cilia covering the whole outer skin, and to the extreme contrac- 

 tility of the muscles of the body-wall. In some locomotion is 

 effected by the proboscis ; this is protruded and attaches itself 

 by means of its spines to some foreign body, after which the 

 body is drawn up after it. This has been specially observed in 

 a land form, Tetrastemma agricola, discovered by Willemoes-Suhm 

 in the Bermudas. On solid bodies the movement is a kind of 

 crawling action, the head and mouth acting as suckers in much 

 the same way as in many Leeches. 



Most Nemertines can be very readily kept in confinement. 

 The chief apparent effect of such a life is a loss of colour, the 

 animal gradually becoming pallid in hue. Owing also to the 

 absence of proper food they diminish very much in size, though 

 even when all food is kept away an animal will sometimes 

 continue to live as long as eighteen months. 



Food. Nemertines are carnivorous in their habits and are 

 very voracious, devouring any prey which comes in their way, 

 whether it be living or dead. No animal food seems to come 

 amiss to them, and they will devour creatures of considerable 

 size. When in contact with its prey, the Nemertine dilates its 

 mouth to a large extent, and the anterior end of the oesophagus is 

 thrust out and engulfs the animal. Chaetopods form a favourite 

 food material, the whole animal being swallowed quite regardless 

 of the hard chitinous bristles and spines with which it is beset. 

 The soft parts are gradually digested, the bristles and other 

 indigestible portions being extruded by the anus. The larger 

 spines often pass out by perforating passages through the wall of 

 the intestine and through the body- wall. The aperture thus 

 formed appears speedily to heal after the foreign body has been 

 extruded. 



The carnivorous habits of Nemertines even extend to canni- 

 balism, and when kept in confinement they frequently devour one 

 another. For this reason it is unsafe to keep large and small 

 kinds together, as the small ones speedily disappear, being used as 

 food material by the large. If one be divided into several pieces, 

 the pieces are very rapidly demolished by other individuals. 



Regeneration. 1 This power is, no doubt, of great service to 

 these animals, since injury, or even violent local irritation, often 

 causes complete rupture at the point affected. It seems that the 

 1 See M'Intosh, British Annelids, Ray Society, 4to, 1873. 



