Hedgehog , an insectivorous mammal, of the genus erinaceus (Linn.). The teeth are 36 in number, but have been differently divided by zoologists. F. Cuvier gives the following : incisors 3/1-3/1, canines none, false molars 3/3/3/3, and true molars 4/4-4/4; according to Owen, they are developed as incisors 3/3-3/3, premolars 4/2-4/2, and molars 3/3-3/3. The central incisors of the upper jaw are separated from each other, those of the lower nearly touching; behind the first upper incisor on each side are two small single-rooted teeth, resembling false molars, but evidently incisors from their development in the intermaxillary bone; after these, and separated from them by a small interval, are three false molars, the first the largest; then the four true molars, the second the largest, the fourth very small, and all tuberculated; in the lower jaw, after the single incisor of each side, are three small single-pointed and single-rooted teeth resembling false molars, and after these, with a short interval, four molars, the second and third the largest; the crowns of the teeth lock into each other, as in other animals preying chiefly on insects.
When full grown, the common hedgehog (E. Europoeus, Linn.) is about 9 in. long, of a heavy form, short limbs, and slow plantigrade motion; the upper part of the body is covered with sharp prickles, about an inch long, arranged in clusters, divergent and crossing each other, of a brownish black with a white point; the head is clothed with harsh brownish hairs, and the under parts of the body with a dirty white fur; the ears and tail are short; the paws, end of nose, and tail are nearly naked; the eyes are prominent, and the opening of the ears may be closed by a valvular arrangement of the cartilages; the nose is considerably longer than the jaws, and fringed at the end; the lips are entire, and there are no cheek pouches; the five toes are armed with long nails, the middle the longest, suitable for digging; the soles are covered with naked tubercles, possessing an exquisite sense of touch; the mammae are ten, six pectoral and four ventral. By means of the development of the pan-niculus carnosus muscle, belonging entirely to the skin, the animal is able to roll itself into a ball, and preserve this attitude as long as it pleases without much effort, presenting to its enemies a thorny mass which the most voracious and powerful dare not attack.
The hedgehog is nocturnal, concealing itself during the day in burrows or natural holes, coming out at night in search of worms, insects, snails, roots, and fruits ; though possessing very limited intelligence, it has been so far domesticated as to he brought up in gardens, where it proves of great service in destroying noxious insects; the flesh is said to be good eating. The young are born in May, covered with prickles, with eyes and ears closed, and about two inches long. When at rest, the hedgehog has the power of lowering the prickles, and of retaining them smooth on a level with the body. This species occurs throughout temperate Europe, and was well known to the ancients. The popular name urchin and the French herisson are evidently derived from the Latin ericius, of which erinaceus is a synonyme; it is the of the Greeks. The prickles were formerly used to hatchel hemp. A second species, the long-eared hedgehog (E. auritus, Pall.), is found in the eastern regions of the Russian empire ; the ears are nearly as long as the head ; the body and limbs are more slender, and the under hair finer, than in the preceding species. Like the other hedgehog, it hibernates in winter in holes a few inches below the surface of the ground ; it can eat cantharides and other vesicating insects with impunity; it grows very fat in autumn, preparatory to hibernating. Other species are described. There is no proper hedgehog in America; the rodent porcupine, similarly armed with quills, is erroneously so called in some parts of the United States.
Hedgehog (Erinaceus Europaeus).