CHAPTER XIX. 



THE EARTHWORM 



Earthworms are found in practically all parts of the country, living 

 in burrows not lower than 12 or 18 inches beneath the earth's surface. 

 It is in about these depths that they find the richest portions of decay- 

 ing vegetable and animal substances upon which they feed. Professor 

 Latter has given us a most interesting account of these animals. During 

 "periods of prolonged drought or frost they descend to greater depths 

 and undergo aestivation ( ) or hibernation 



( ), as the case may be, coiled up into a com- 



pact spiral and lying in a small excavated chamber. This is lined with 

 small stones which prevent close contact with the surrounding earth 

 and so permit free respiration. The sides of the burrow are kept moist 

 by slime discharged from the glandular cells of the skin, and perhaps 

 by liquid discharged from the body-cavity through the dorsal pores 

 which occur in the grooves that separate segment from segment. The 

 slime is said to possess antiseptic properties, and thus preserve the skin 

 of the worm from harmful bacteria. 



"The mouth of the burrow is guarded by small stones or more fre- 

 quently by one or more leaves pulled in to a greater or less distance. 

 Fir-needles, stalks of horse-chestnut leaves and other similar things are 

 often to be seen standing nearly erect upon the ground, their lower ends 

 having been forcibly dragged into the mouth of a burrow by a worm. 

 On still, warm nights in early autumn the rustling noise of fallen leaves 

 being dragged along by worms is often plainly audible in favorable 

 localities. Darwin has pointed out that worms exhibit considerable in- 

 telligence in drawing the narrow end of leaves of various shapes fore- 

 most into the burrow : the leaves with broad bases and narrow apices 

 are generally pulled in tip first, whereas when the base is narrower than 

 the apex the reverse position is usually found. There is no doubt that 

 worms can judge which end of any leaf is the better to seize. The 

 reason for thus pulling objects into the entrance of the burrow is prob- 

 ably to prevent the entry of foes, centipedes, parasitic flies, etc., to keep 

 the burrow moist by preventing evaporation, to keep out the cold lower 

 strata of air at night, to bring food supplies within safe reach, and also 

 to enable the worms to lie near the mouth of the burrow unobserved. 

 Here, however, they are not secure from all attack, for the quick ears 

 of the thrush and other birds enable them to detect the slightest move- 

 ment and, with a quick plunge of the beak, to seize, and after a brief 

 tug-of-war, to extract the worm from its refuge. Frequently the well- 

 known worm-castings are thrown up on the surface, and when this is so, 



