THE BAND-WORM. 171 



semi-aquatic life of the animal, while the earthworm respires 

 through internal pulmonary vesicles. Both worms have neither 

 the eyes nor the antennae nor the well-armed jaws which dis- 

 tinguish the higher orders of the class, and are thus no better 

 than plebeians in the little commonwealth of the annelides. 

 The turbellarise and the intestinal worms, however, stand on a 

 still lower step of organic development ; for the former, which 

 are partly, like the nemertinse, of an elongated wormlike form of 

 body, partly of a flattened shape, like the planarise, show no 

 trace of segments or rings, and being entirely deprived of pecu- 

 liar respiratory organs, breathe merely through the entire out- 

 ward surface of their naked bodies. 



The great band-worm (Nemertes gigas) is one of the most 

 remarkable examples of this low type of annelism. It is from 

 thirty to forty feet long, about half an inch broad, flat like a 

 ribbon, of brown or violet colour, and smooth and shining like 

 lackered leather. Among the loose boulders or in the crevices 

 of submerged rocks, where it feasts on minute shells and other 

 tiny creatures of the deep, this gigantic sea-worm forms a thou- 

 sand seemingly inextricable knots, which it is constantly un- 

 ravelling and tying. When after having devoured all the food 

 within its reach, or from some other cause, it desires to shift its 

 quarters, it stretches out a long dark-coloured ribbon, surmounted 

 by a head like that of a snake, but without its wide mouth or 

 dangerous fangs. The eye of the observer detects no muscular 

 contraction, sees no apparent cause or instrument of locomotion; 

 but the microscope, the mighty revealer of hidden wonders, shows 

 him that the innumerable vibratory ciliaB with which the whole 

 body of the nemertes is covered cause it to glide along. The 

 creature hesitates, tries here and there, until at last, and often 

 at a distance of fifteen or twenty feet, it finds a stone to its taste, 

 whereupon it slowly unrolls its length, to convey itself to its new 

 resting-place or pasture-ground ; and while the entangled folds 

 are unravelling themselves at one end, they form a new gordian- 

 knot at the other. Thus, in spite of the extreme simplicity of 

 its organisation, the band-worm is fully equipped with all the 

 means of existence, and the eye of its All-seeing Maker directs 

 it, though blind, to its food. 



In spite of their abject mode of life, the intestinal worms 

 must be reckoned in many respects among the great marvels of 



