180 



ZOOGENE-ZOOLOGT. 



tropics ; that is, the circles in which the BUD reaches 

 its greatest distance from the equator. As the rays 

 of the sun here are nearly vertical, a perpetual sum- 

 mer reigns, and day and night, under the equator, 

 are always equal ; and even at the tropics, the dif- 

 ference is scarcely an hour. Owing to the nature 

 and situation, however, of the countries in this 

 zone, the heat is not every where the same. The 

 warmest portions are the sandy deserts of Africaj 

 far more temperate are the happy islands of the 

 South seas, and still milder the climate of Peru. 

 This last country contains mountains from whose 

 summits the vertical sun-beams never melt the per- 

 petual snow. The two temperate zones extend 

 from the tropics to the polar circles. They contain 

 the most populous countries, and the climate is 

 various. As the distance from the tropics increases, 

 the heat diminishes, the difference of the seasons 

 becomes greater, the days and nights become more 

 unequal, until we arrive at a point where, once a 

 year, the sun does not appear above the horizon 

 during the twenty-four hours, and, once a year, 

 does not set for the same time. The circles passing 

 through these points, parallel to the equator and 

 the tropics, form the limits of the temperate zones, 

 and are called the arctic and antarctic circles. The 

 distance from the tropics to the polar circles, or the 

 breadth of the temperate zones, both in the north- 

 ern and southern hemispheres, is 43. All beyond 

 the polar circles, to the poles, is called the frigid 

 Tones. No land is known to exist in the southern 

 frigid zone. The northern is habitable, though it 

 produces neither grain nor trees, but only mosses, 

 lichens, and a few bushes. The distance from the 

 polar circles to the poles is 23 ; but no one has 

 yet penetrated to the poles themselves. Cook 

 sailed as far as the seventy-first degree of latitude, 

 towards the south pole, which is still more inhos- 

 pitable than the north, as its winters occur at the 

 time of the earth's greatest distance from the sun. 

 To the north, the eightieth degree has been reached. 

 (See North Polar Expeditions.) The character- 

 istic of the frigid zones is, that day and night are 

 more and more unequal the nearer you approach the 

 poles ; and for days, and even weeks, the sun is 

 above or below the horizon. See Seasons. 



ZOOGENE (from av, animal, and ymau, to 

 produce). On the surface of the thermal waters 

 of Baden, in Germany, and on the waters of Ischia, 

 an island of the kingdom of Naples, a singular sub- 

 stance is collected, which has been called zoogene. 

 It resembles human flesh with the skin upon it. 

 and, on being subjected to distillation, affords the 

 same products as animal matter. M. Gimbernat 

 (Journal de Pharmacie, April, 1821) has also seen 

 rocks covered with this substance, in the valleys of 

 Sinigaglia and Negropont. Salverte (Des Sciences 

 Occultes, 1829, 2 vols., 8vo.) considers this fact as 

 explaining the stories of showers of pieces of meat, 

 which figure in the number of prodigies of antiquity. 



The name of zoogene is also given to a substance 

 obtained from bones, by a chemical process which 

 was discovered by M. Gimbernat. Much of it was 

 sent, in 1827, to Greece, and much of it also was 

 used by the French army, on the expedition to Al- 

 giers. 



ZOOLITHES (from , animal, and lifts, 

 stone) : fossil animal remains, great numbers of 

 which have been found in digging into the surface 

 of the earth. They differ from petrifactions, which 

 are organized bodies, penetrated with stony matter, 

 or completely converted into stony masses, by the 



gradual removal of the organic matter, the place of 

 which has been supplied by stony deposits. Zooli- 

 thes have been divided into six classes tetrapodo- 

 lithes, or fossil quadrupeds ; ornitholithes, or fossil 

 skeletons of birds ; amphilriolithes, or fossil remains 

 of the amphibia ; ichtht/olithes, or fossil fish ; ento- 

 molithes, or fossil insects; and helmintholitlies, or 

 fossil worms. See Geology, and Organic Remains. 

 ZOOLOGY (from *, animal, and *.eycs, doc- 

 trine) ; that part of natural history whirl) treats of 

 animals. It is not confined to a description of the 

 external forms of animals, but embraces all the 

 phenomena of life and animal motion ; tlie internal 

 organization of each individual part ; the proi 

 of digestion, assimilation, nutrition, secretion and 

 reproduction; the wonderful instincts, the varied 

 dispositions, and the different degrees of intellect, 

 manifested in the animal creation, from the half- 

 vegetable zoophyte, up to man. Although it can- 

 not be doubted that the attention of men was early 

 attracted to an observation of the habits and natures 

 of the lower order of animals, Aristotle seems to 

 have been the first who furnished the world with 

 any methodical information on this subject. His 

 work nij/ z.v 'Ifrofiai contains a great number of 

 facts and observations. He compares the organiza- 

 tion of the lower animals, in its different parts, 

 with that of man, and treats of their mode of gene- 

 ration, habits, organs, &c., with great clearness and 

 sagacity ; and his principal divisions of the aniintil 

 kingdom are so well founded that almost all of 

 them are still substantially admitted. Among the 

 Romans, zoology does not appear to have been at 

 all cultivated, until the time of Pliny, who is the 

 only Roman zoologist worthy of notice. His work 

 (Historia Naturalis") contains multitudes of oripiiiiil 

 traits, though it is only a compilation, and describes 

 the habits and dispositions of animals with p-cat 

 felicity. He adopted, without examination, many 

 fabulous stories, and too often neglected important 

 details. ./Elian (q. v.) was far inferior to the two 

 above-mentioned writers, and his Natural History 

 of Animals may be considered as the source of all 

 the falsehood and error which so long disgraced this 

 branch of natural history. A puleius, and Athenaeus 

 the grammarian, are the only names that deserve 

 mention, from the time of JElian and Pliny to the 

 beginning of the sixteenth century ; and they added 

 nothing to the stock of zoological science. At the 

 latter period, flourished, among others, Belon, a 

 French physician, who made the closest approach of 

 any author of that time to any thing like systematic 

 classification, in his De Aquatilibus, and particular- 

 ly in his De la Nature des Oiseaux (Paris, 1555, 

 folio) ; Salviani, author of a treatise, Aquatilitan 

 Animalium Historia (Rome, 1554, folio), which is 

 superbly illustrated ; Conrad Gesner, whose His- 

 toria Animalium (Zurich,'1550 1587,4 vols., folio), 

 arranged in alphabetical order, forms the founda- 

 tion of modern zoology ; and Aldovrandus* the 

 most laborious of compilers, who devoted sixty 

 years to his work on natural history, in fourteen 

 volumes, folio, of which the greater part was pub- 

 lished after his death. These earlier writers were 

 followed, in the next century, by Redi and Swam- 

 merdam, to whom entomology is so much indebted, 

 and by Ray (q. v.), the first naturalist, from the 

 time of Aristotle, who produced any thing like a 

 scientific arrangement. The works of Ray, under 

 his own name, are Synopsis Qvadrvpedum et Ser- 

 \pentum (1683, 8vo.); Synopsis Avium et Piscivm 

 \ (1713) ; and Historia Insectorum ; and he is also 



