Page:The American Cyclopædia (1879) Volume VI.djvu/379

 K I EARTH WORM remarkable ; the sexes are united in the same individual. During the breeding season, from six to nine of the segments (from the 26th to the 37th, as generally described) are developed into a kind of collar, nearly surrounding the body, by which these animals seize each other during coition ; its component glandular folli- cles secrete a whitish viscid fluid, probably used for the formation of their cocoons or egg cases. According to Dufour, these cocoons have a long narrow neck, each, in the largest species, containing from one to six eggs ; the statement of Montegre that the young are born alive seems to be confirmed by the obser- vations of Dr. Williams, who says that they escape from the egg before leaving the body of the parent. It seems certain from the ex- periments of Dufour (Annales des sciences na- turelles, t. v. p. 17, and t. xiv. p. 216, 1st se- ries) that the earth worm reproduces by means of eggs ; he describes them as an inch in length, of a corneo-membraneous consistence, deposited in the earth at a depth of from 6 in. to 6 ft., in localities where the soil is neither inundated nor too dry, isolated, and each egg containing one or two young. Earth worms live in moist earth, in which they make gal- leries in all directions, swallowing the earth as they proceed ; thert food is principally soft and decaying vegetables, as may be proved by any one who chooses to watch a garden walk by the light of a lantern on a damp evening, when they may be seen creeping out of their holes, elongating their first tactile segment, feel- ing in all directions for food, and, seizing upon any suitable substance that presents itself with their projected proboscis, retiring backward into the ground; their constant presence in situations where there is decaying vegetable matter proves that their food is principally derived from such substances; they also, as Montegre observed, feed on animal matters; it seems more reasonable to believe, with De Blainville, that they swallow earth for the pur- ose of making progress in their galleries, than ihat they do this to extract humus or any other nutritious substance from it. They seek each other chiefly at night and in the latter part of spring, though some species have been noticed e warm months; it is well known that they are most abundant on the surface of the ground during and after nocturnal rains. It has long been believed that this animal possesses a re- kable power of reproducing parts lost by ident or design, even to the extent of form- perfect individuals from separated portions; e experiments of Duges prove that very im- tant parts may be reproduced, and it may lily be believed that in a worm divided into two, the anterior portion might produce an anus by the simple contraction of the wound ; but that the posterior portion should be able to reproduce cerebral ganglia, mouth, stomach, cardiac and sexual organs, cannot be admitted ; the anterior may survive a long time, but the EAR TRUMPET 371 posterior division gradually dries up and dies. Though occasionally marring the beauty of the garden walks by little hillocks of earth, they not only do not injure vegetation, but are useful in permitting air and water to penetrate the ground through the channels which they pierce in every direction, manuring the fields, and throwing up fine dirt around the roots of grass ; a field in which no worms exist can be safely put down as of little value to the agri- culturist; they are most active in spring, when most needed, and retire during winter deep into the ground; according to Mr. Darwin, they perform under ground that which the plough and the spade do on the surface, and have covered a field manured with marl, in the course of 80 years, with a bed of earth 13 inches thick. Worms also furnish food for birds, moles, frogs, and other small animals, and are used as bait for many kinds of fish. The rapid ascent and descent of worms in the ground are easily understood from the action of their numerous seta? ; they have often been seen high up on perpendicular surfaces, and in situations which they could not have reached without climbing perpendicularly. In their movements they display great muscular force, each seta being moved by its appropriate sys- tem of muscles, and being capable of penetra- ting a deal board ; in ascending perpendicular surfaces of glass or other impenetrable material, they must retain their hold by means of the tenacious mucus with which their skin is cov- ered. There is no question that many species have been confounded under L. terrestris (Linn.). The largest European species is called L. gigas, and is 18 in. long, and as large as the little finger ; other common and smaller species are L. anatomicus and L. trapezoides. Whe- ther all the American species are distinct has not been sufficiently demonstrated. Those who wish to pursue this subject into its details are referred to the writings of Dufour, Duges, Milne-Edwards, Blanchard, and especially Qua- trefages in the Annales des sciences naturelles since 1828; to the article "Annelids," in the "Cyclopaedia of Anatomy and Physiology;" to the report of Dr. Williams, above quoted ; and to Siebold's " Comparative Anatomy." EAR TRUMPET, an instrument intended to aid the hearing of persons partially deaf, al- though sometimes used by ordinary persons to intensify distant sounds. We have no means of ascertaining at what period or by whom ear trumpets were invented. The practice of put- ting the hand to the ear in a trumpet shape probably first suggested it, and from occasional allusions to the use of the trumpet in old wri- ters it would seem to have been of very early origin. The earliest form of which we have any knowledge was a rude imitation on an exaggerated scale of the form of the external ear ; but as this was found inconvenient from the difficulty of retaining it in place, a form more nearly resembling a speaking trumpet was substituted. This was modified by bend-
 * ether at all times of the day, and during all