RELATION OF EARTH WORMS TO HORTICULTURE. 97 



cence in the sunshine, due to the breaking up of the rays of light by 

 the numerous rings or constrictions. As the worm breathes by gill-like 

 organs, its body must always be kept moist, so an immense amount of 

 mucous or slime is secreted from its whole surface. Just underneath 

 the second joint of the head a peculiar slit or opening marks the posi- 

 tion of the mouth ; this opens into an enlarged tube leading to the 

 stomach, which tube, because of its occasional protrusion for the 

 seizure of food, is called the proboscis. The stomach is a mere en- 

 largement of the intestine, and together with the latter passes as a 

 straight tube to the posterior end of the body. Just in front of the 

 stomach are two large branched glands, which, from the fact that they 

 «ecrete immense quantities of a solution of carbonate of lime, are 

 called the calciferous glands. The function of this secretion is believed 

 to be the neutralizing of acid food, as it is frequently thrown out to 

 cover such food. It undoubtedly- aids in the digestion of the food out- 

 side of the body, and is the only case, as far as known, of extra-stom- 

 achal digestion. By placing an earth worm on a plate and watching the 

 peculiar wriggling motion, a row of minute spines may be noticed on 

 either side of the body. These can be readily felt by drawing a worm 

 through the fingers from head to tail. These bristles are worked by a 

 complicated set of muscles which makes locomotion very rapid. Every 

 schoolboy who has ever dug worms for bait will testify to the rapidity 

 with which a worm can escape pursuit, and this is the way that it is 

 •done ; Expanding the body posteriorly, the bristles are fastened, like 

 so many little anchors, holding that end in the soil ; by another set of 

 muscles the anterior end is elongated to a certain distance, and there 

 anchored by means of the bristles, when the rest of the body is drawn 

 up to it, and the process repeated indefinitely. When the worm moves 

 rapidly it may eat large quantities of soil, from which it assimilates 

 whatever nourishing organic matter it may contain. This earth is fre- 

 quently discharged at the surface of the ground in irregular, coiled 

 dirt-castings, so commonly seen around small holes on our lawns and 

 in the gardens ; it is not uncommon to see as many as six or eight of 

 these little mounds in the space of one square foot, from which we may 

 infer something of the quantity of soil thus brought from below to the 

 surface of the earth. 



Von Hensen studied these little animals for several years, and to 

 him, as well as to Darwin, are we greatly indebted for our present 

 knowledge. He describes their habits in a most interesting manner, 

 stating that it is mainly at night and during damp weather that they 



H. R.— 7 



