ICE PLANT ICHTHYOLOGY. 



33 



Northern History ; Fin Johnson's Hist. Eccles. Is- 

 landicee ; and Eichhorn's Alg. Geschichte der Lite- 

 ratur. 



ICELAND MOSS. See Lichen. 



ICE PLANT (mesembryanthemum crystallinum). 

 This singular plant has received the above appella- 

 tion from the little transparent vesicles which cover 

 its whole surface. The stems are herbaceous, as 

 large as the little finger, spread upon the ground, 

 and very much ramified ; the flowers are white, and, 

 as in the rest of the genus, furnished with a great 

 number of linear petals, which give them the appear- 

 ance of compound flowers, though belonging to a 

 very different family. It is a native of the sea-coast 

 of South Africa, the Canaries, and is also found in 

 the vicinity of Athens. The other species of mesem- 

 bryanthemum, upwards of 300 in number, forming 

 one of the most numerous and remarkable genera of 

 plants, are, almost without exception, confined to 

 South Africa, and constitute a marked feature in its 

 vegetation. 



ICETAS ; tyrant of Leontini, who caused the 

 sister and wife of Dion, who had fled to him for pro- 

 tection, to be thrown into the sea. He was called 

 in by the Syracusans against the tyrant Dionysius, 

 whom he defeated. But his ambitious designs in- 

 duced the Syracusans to have recourse to the Corin- 

 thians, under Timoleon (q. v.), who defeated Icetas 

 (345 B. C.). forced him to resign his power, and re- 

 nounce his league with the Carthaginians. Having 

 aain taken arms against Timoleon, he was captured 

 and put to death, with his wife and children. 



ICHNEUMON (herpestes, Illig.} These animais 

 belong to the civet family, and are distinguished from 

 their kindred genera by their narrower and more 

 pointed muzzle ; by the shape of their lower lip, and, 

 more especially, by the absence of the double cavity 

 beneath the tail, which is replaced by a single pouch, 

 of considerable size, but destitute of secreting glands. 

 Their hair is long, brittle, and generally variegated 

 in colour. The ordinary colour of its coat is chest- 

 nut brown and fawn ; nose and paws, deep chestnut 

 or black. It is about eighteen inches from the snout 

 to the root of the tail. The habits of the ichneumon 

 are very similar to those of the ferret. In the coun- 

 tries where they are found, their sanguinary disposi- 

 tion and predatory habits render them a great annoy- 

 ance to the inhabitants, from the destruction they 

 cause among the poultry. This is, however, com- 

 pensated, in some degree, by the incessant war they 

 wage against reptiles, the eggs of which they devour 

 with great avidity. The most celebrated species 

 inhabits Egypt and the adjacent countries, where it 

 is called Pharaoh's rat. It is very common in the 

 northern parts of Egypt, between the Mediterranean 

 and Sioat. It is of a grey colour, and has a long tail, 

 terminated by a black tuft ; it is larger than a cat, 

 but formed like the weasel. This species was ranked 

 by the ancient Egyptians amongst their numerous 

 divinities, on account, it is supposed, of the benefits 

 which it confers on man by the destruction of croco- 

 diles, whose eggs it digs out of the sand and sucks. 

 The story of its overcoming these formidable reptiles 

 themselves, by gliding down their throats, is, of 

 course, a mere fable. Many other fabulous stories 

 are related of the ichneumon by the Greek and Roman 

 writers, Herodotus, ./Elian, Diodorus, Pliny, &c. 

 The ichneumon is exceedingly expert in seizing ser- 

 pents by the neck, in such a manner as to avoid any 

 injury to themselves. Lucan alludes to this (in lib. 

 iv. 724,) in speaking of the asp. The ichneumon is 

 domesticated and kept in the houses in Egypt, and is 

 more useful than a cat in destroying rats and mice. 

 They grow very tame, are exceedingly active, spring- 

 ing on their prey with great agility. They often 



squat on their haunches, and feed themselves with 

 their fore-paws, like a squirrel. They are great 

 enemies to poultry, and will often feign themselves 

 dead till their prey comes within reach. Like 

 the cat, they are great lovers of fish. When they 

 sleep, they bring their head and tail under their belly, 

 and appear like a round ball. Their voice is very 

 soft, somewhat like a murmur, and, unless they be 

 struck or irritated, they never exert it. Their great 

 disadvantage, as domestic animals, is their unconquer- 

 able predilection for poultry, which they destroy 

 whenever they have an opportunity, for the purpose 

 of sucking their blood. In a wild state, they swim 

 and dive in the manner of an otter, continuing be- 

 neath the water for a great length of time, ana sup- 

 port themselves by fishing. These animals are short- 

 lived, but grow very rapidly. 



ICHNEUMON is also the name of a large genus 

 of insects, belonging to the great order of hymenop- 

 tera. As the species of this genus are very numer- 

 ous, so their manners are extremely diversified ; but, 

 in the general outlines of their character, they all 

 agree, particularly in their depredations among the 

 insect tribes. In some, the female has a wimble at- 

 tached to her abdomen, and with this instrument, 

 delicate as it appears, she is capable of perforating 

 the hardest substances. The larvae of wasps are the 

 devoted prey of these insects, who no sooner discover 

 one of their nests, than they perforate the clay, of 

 which it is constructed, and deposit their eggs within 

 it. Others glue their ova to the skin of a caterpillar, 

 whilst others again penetrate through it, and lay their 

 eggs in its body. In all these cases, the young, as soon 

 as they are hatched, prey on the caterpillar or larvae, 

 without, however, destroying it at once, as upon the 

 life of its victim that of the spoiler appears to depend. 

 The caterpillar, in fact, seems healthy, until the 

 larvae of the ichneumon have spun their cocoons, and 

 entered the chrysalis state. We often see cater- 

 pillars fixed to a leaf or branch by the threads spun 

 by the ichneumon. These carnivorous insects are of 

 various sizes ; some are so small that the aphis, or 

 plant-louse, serves as a cradle for their young ; others 

 again, from their size and strength, are formidable 

 even to the spider, destroying them with their 

 powerful stings. 



ICHTHYOLOGY. This term is derived from 

 i%$vs, a fish and Aaya;, a discourse. According to the 

 system of Cuvier Ichthyology embraces the FOURTH 

 order of vertebrate animals ; or all the extensive 

 class of fishes, consisting of oviparous animals with 

 a double circulation. 



Fishes have been used as an article of food from 

 the earliest ages. Aristotle was the first writer who 

 formed them into a distinct class ; but we are indebted 

 to Pliny for the earliest accounts of their characters 

 and habits. Nothing of any importance appears to 

 have been written on this branch of natural history, 

 for a long series of years after the time of Pliny, until 

 the publication of Below's work, which was printed 

 in 1551, entitled Histoire des Poissons, wherein he 

 grouped fishes into four families ; namely, cartilagi- 

 nous flat fishes ; flat fishes, which were not cartilagi- 

 nous ; the third was sharks, and their congeners ; 

 and the fourth, eels and other fishes with elongated 

 bodies. 



In 1554, the work of William Rondelet, professor 

 of medicine at Montpellier, was published, where- 

 in he gave most accurate specific accounts of the 

 animals, but did but little to improve the classifica- 

 tion. Shortly after appeared the Aquatilium Ani- 

 malium Historia of Hippolyto Salviani. The taste for 

 the study of Ichthyology seems to have taken its rise 

 at this period. In the year 1C38, Aldrovandus pub- 

 lished a work on fishes ; and Willughby in 1686, pub- 



