214) Natural History of the Earth- Worm, 



The earth-worm moves along the surface, or in the soil, by al- 

 ternate elongations and contractions of a determinate portion of 

 the body. Stretching forward the anterior extremity to the ut- 

 most, it is then fixed against the ground by means of the lateral 

 bristles, and now the rest of the body is drawn to the fixed 

 point. It can move backwards or forwards with nearly equal 

 facility ; and, when seized in its progress, it wriggles and twists 

 itself into many coiled knots and circles. This it does also when 

 wounded, and its writhings surely indicate a severe degree of 

 suffering in the poor worm, which is too often wantonly trod upon. 

 The movements of the earth-worm in its burrow are performed 

 with much greater rapidity than on the surface, a superiority 

 which results from the disposition of the bristles along the sides, 

 for in a circular tube alone can they all be brought into action 

 and made to act as fulcra, the animal having the power of pro- 

 truding them to a slight extent. Hence, we find that the hole 

 of the worm is of the same figui'e as its body, and nearly of the 

 same calibre, that the ascent and descent may be retarded neither 

 by over-straitness, nor by a wideness which would render the 

 contact of the bristles against its walls impossible. The holes 

 are in general sinuous and worked in an oblique direction, and 

 lined with the slimy juice which exudes from the animal. They 

 vary in depth from a few inches to upwards of 4 ft., and have 

 two, or even occasionally several, apertures, of which one is the 

 vent whence they eject those vermicular pellets of earth that have 

 passed through the intestine, and are in fact moulded and 

 fashioned within it. 



The mode in which the earth-worm burrows is this. The 

 anterior extremity of the worm forms a cone, gradually tapering 

 from a little in front of the belt to the snout, which is formed by 

 the upper lip being somewhat elongated over the mouth, like a 

 short proboscis. As this can be shortened and thickened, or 

 made gracile and sharp at will, we can understand its fitness as 

 an auger, and its equal aptness for making a hole rather larger 

 than the body when relaxed and undistended. Wishing to 

 burrow, and having selected a soft moist earth, the worm 

 stretches forward this anterior portion of its body and stiffens it. 

 It now pouts out the upper lip, and rendering it, too, tense and 

 elastic, the worm pushes it under the soil or clod, raises it, and 

 casts it aside : then again it digs and loosens another portion of 

 earth until, by many repetitions and much patience, the tunnel 

 is insensibly completed. As the worm swallows the great pro- 

 portion of the soil raised in the progress of its work. Nature has 

 given it no instruments for the removal of the obstacle, such as 

 have been gifted to many other boring insects. 



The reproductive organs of the earth-worm coexist in every 

 individual ; but the copulation of two is required to impregnate 



