692 IIEROPHILUS chines, among which are the fountain called by his name, in which a jet of water is kept playing by means of condensed air ; a steam en- gine, on the principle of what is called Bar- ker's mill, in which the boiler is caused to re- volve round a vertical axis by jets of steam issuing from, lateral holes in the arms with which it is provided ; and a double forcing pump used for a fire engine. Heron wrote several works on mechanical and scientific sub- jects, of which only fragments remain; the most valuable is his HvevfiariKd, or treatise on pneumatics, the best edition of which is that published at Paris in 1693, in the Veterum Ma- thematicorum Opera. IIEROPHILUS, a Greek anatomist, born at Ohalcedon in Bithynia, flourished about 300 B. C. He lived at Alexandria, where he ac- quired great reputation both as a teacher and practitioner. He is generally thought to have been the first who actually studied and taught anatomy from the dissection of human bodies ; and he no doubt practised this method to a far greater extent than had previously been done. His investigations in human anatomy were marked by so much originality and exactness, that a large number of the anatomical names now in use date from him. He first distin- guished the nerves from the tendons, with which they had previously been confounded, and showed that they originate from the brain. He recognized the principal membranes of the brain and the eyeballs, and gave them their names of arachnoid, retina, &c. The conflu- ence of the great longitudinal and lateral si- nuses of the brain is still called the torcular Herophili; and the first division of the small intestine retains the designation, duodenum, which he gave to it. He is also said to have examined to some extent the internal organs, for the purpose of investigating the nature and cause of the disease which produced death ; thus laying the foundation of the science of pathological anatomy, the study of which was recommenced by Morgagni, 2,000 years later. The original works of Herophilus have long been lost, with the exception of a few frag- ments, and are now known mainly through quotations by Galen and others. IIKKOSTR ATI S. See EROSTRATUS. HERPETOLOGY (Gr. ipirerbv, reptile or creep- ing thing, and Arfyo?, discourse), the branch of zoology which treats of the structure and clas- sification of reptiles. The present article will be confined to the last division, the first being more properly noticed under REPTILES. The Egyptian and other ancient authors knew well the distinctions between the four reptilian or- ders, generally called tortoises, lizards, ser- pents, and frogs; Aristotle described them as terrestrial, red-blooded animals, laying eggs, and with four or no feet, mentioning tortoises, frogs, crocodiles, lizards, and serpents, and in- dicating the first three as amphibians. Pliny, four centuries later, divided reptiles into ter- restrial, aquatic, and aerial, but he has mostly HERPETOLOGY copied Aristotle, adding a great variety of fab- ulous stories whose influence has extended in the popular mind even to the present time. Gesner, in the 16th century, devoted a consid- erable part of his writings to the natural history of this class, illustrated with wood engravings, and conveniently arranged in alphabetical order. Aldrovandus, toward the end of the same century, wrote two books on serpents and lizards, compiling chiefly from the Greek and Arabian authors, and collected much in- formation from the synonymy of reptiles, their symbolic history, and their uses in medicine. Ray published in London, in 1693, a synopsis of serpents, in which the manner of respira- tion, the size and color of the eggs, and similar characters, are made the basis of an unnatural classification. Linnaeus divided the class of reptiles into orders, genera, and species in his Systema Natures; calling them, however, am- phibia, and characterizing them by the three principal marks of naked or scaly body, teeth sharp and without molars, and no fins with rays; he made two orders, serpents (without limbs) and reptiles (with limbs). In his third class, as given in Gmelin's edition of 1788, the order reptiles are those breathing by lungs, with four limbs, and a simple male sexual organ; serpents, on the other hand, have a rounded body without distinct neck, moving by its undulations, with dilatable and non-con- solidated jaws, and without limbs, fins, or ex- ternal ears. In the first order were four gen- era, the tortoise, dragon, lizard, and frog ; and in the second, crotalus, boa, coluber, anguis, amphisbcena, and ccecilia, most of these genera being subdivided into numerous species. Lau- renti, in 1768, published a synopsis of reptiles, very remarkable for the time. Leaving tor- toises out of the class, he gives their characters as follows: cold-blooded animals, without hair or mammae, with lungs acting without dia- phragm and almost without the aid of the ribs (swallowing air into them), torpid in winter, devouring their prey without chewing, and di- gesting it very slowly, able to exist for months without food, and renewing their youth by changing their skins. Lac6pede, in 1788-'9, in a work continuing that of Bnffon, entitled Histoire naturelle des quadrupedes ovipares et des serpents, divided reptiles into four classes tailed and tailless oviparous quadrupeds, biped reptiles, and serpents; the first con- taining the tortoises and saurians, the second the frogs and toads, the third and fourth being sufficiently characterized by the names; he made only 292 species. Alexandre Brongniart, in 1799, taking into consideration not only the external characters but those presented by the mode of generation and development, divided reptiles into the four orders of chelonians, sau- rians, ophidians, and batrachians. In 1800 Du- me>il introduced into the first volume of his Le~ fons d'anatomie comparee a classification adopt- ing the names of Brongniart, and separating the batrachians as a distinct order. Daudin,
