432 K E P R E P REPSOLD, a family of German instrument makers. JOHANN GEORG REPSOLD (1771-1830), was born at Wremen in Hanover on September 23, 1771, became an engineer and afterwards chief of the fire brigade in Hamburg, where he started business as an instrument maker early in the present century. He was killed by the fall of a wall during a fire on January 14, 1830. The busi- ness has been continued by his sons Georg and Adolf and his grandsons Johannes and Oscar. J. O. Repsold introduced essential improvements in the meridian circles by substituting microscopes (on Ramsden'a plan) lor the vr- i niers to read the circles, and by making the various parts perfc< -tlv symmetrical. For a number of years the lirm was foremost in this special branch and furnished meridian circles to the observatories at Hamburg, Kbnigsberg, Pulkova, &c. ; later on the activity in this direction declined, while Pistor and Martins of Berlin rose to emi- nence in the manufacturing of transit circles. But after the discon- tinuance of this firm that of Repsold has again come to the front, not only in the construction of transit circles, but also of equatorial mountings and more especially of heliometers (see MICROMETER). REPTILES A NTELINN^EAN writers comprised the animals which JTjL popularly are known as Tortoises and Turtles, Croco- diles, Lizards and Snakes, Frogs and Toads, Newts and Sala- manders, under the name of Oviparous Quadrupeds or four- limbed animals which lay eggs. Linnaeus, desirous of giving expression to the extraordinary fact that many of these animals pass part of their life in the water and part on land, 1 substituted the name of Amphibia for the ancient term. Subsequent French naturalists (Lyonnet 2 and Brisson 3 ) considered that the creeping mode of locomotion was a more general characteristic of the class than their amphibious habits, and consequently proposed the scarcely more appropriate name of Reptiles. As naturalists gradually comprehended the wide gap existing between Frogs, Toads, <fcc., on the one hand, and the other Oviparous Quadrupeds on the other, they either adopted the name of Batrachia for the former and that of Amphibia for the latter, or they restricted the term Amphibia to Batrachians, calling the remainder of these creatures Reptiles. Thus the term Amphibia, as used by various authors, may apply (1) to all the various animals mentioned, or (2) to Batrachians only and thus it has been used in the article AMPHIBIA in the present work. The term Reptiles is used (1) by some for all the animals mentioned above, and (2) by others, as in the present article, for the same assemblage of animals after the ex- clusion of Batrachians. Other terms more or less synony- mous with Amphibians and Reptiles in their different senses have been used by the various systematists, as we shall see hereafter. Equally varying are the limits of the term " Saurians," which occurs so frequently in every herpetological treatise. At first it comprised living Crocodiles and Lizards only, with which a number of fossil forms were gradually associ- ated. As the characters and affinities of the latter became better known, some of them were withdrawn from the Sau- rians, and at present it is best to abandon the term alto- gether. HISTORY AND LITERATURE. a. T/te Gemral Subject. By some feature of their organization or some peculiarity in their economy Reptiles have always forced themselves upon the observation of man or excited his imagination, so that certain kinds are mentioned in the earliest written records or have found a place among the fragments of the oldest relics of human art. Such evidences of a popular knowledge of Reptiles, however, form no part of a succinct review of the literature of the subject such as it is proposed to give here. We distinguish in it five periods : (1) the Aristotelian ;__ (2) the Linnaean (formation of a class Amphibia, in which Reptiles and Batrachians are mixed); (3) the period of the elimination of Batrachians as one of Polymorpha in his amphibiis natura duplicem vitam plerisque concessit." 2 Theologie des Insectes de Lesser (Paris, 1745), i. 91, note 5. 3 Regne animal divise en tituf classes (Paris, 1756). the Reptilian orders (Brongniart) ; (4) that of the separa- tion of Reptiles and Batrachians as distinct subclasses ; (5) that of the recognition of a class Keptilia as part of the Sauropsida (Huxley). 1. The Aristotelian Period. As in other branches of Aristoi zoology, we have to start with ARISTOTLE, who was the first to deal with the Reptiles known to him as members of a distinct portion of the animal kingdom, and to point out the characteristics by which they resemble each other and differ from other vertebrate and invertebrate animals. As the plan of his work, however, was rather that of a comparative treatise of the anatomical and physiological characters of animals than their systematic arrangement and definition, his ideas about the various groups of Reptiles are not distinctly expressed, but must be gleaned from the terms which he employs. And even when we make due allowance for the fact that we are in posses- sion of only a part of his writings, we cannot but per- ceive that he paid less attention to the study of Reptiles than to that of other classes ; this is probably due to the limited number of kinds with which he could be ac- quainted from the fauna of his own country, and to which only very few extra-European forms, like the Crocodile, were added from other sources. And, whilst we find in some respects a most remarkable accuracy of knowledge, there is sufficient evidence that he neglected every-day op- portunities of information, as if Reptiles had not been a favourite study. Thus, he has not a single word about the metamorphoses of Batrachians, which he treats of in connexion with Reptiles. Aristotle makes a clear distinction between the scute or scale of a Reptile, which he describes as </>oAis, and that of a Fish, which he designates as XeTrt's. He mentions Reptiles (1) as oviparous quadrupeds with scutes, viz., Saurians and Chelonians ; (2) as oviparous apodals, viz., Snakes ; (3) as oviparous quadrupeds without scutes, viz., Batrachians. He considered the first and second of these three groups as much more nearly related to each other than to the third. He says : "The genus of Snakes resembles that of Lizards, nearly all the characters being common to both, if the Lizard be conceived of as prolonged and without legs. They possess scutes, and arc similar to Lizards above and below, but they lack testicles ; and, like Fishes, they possess two excretory ducts which coalesce, and the uterus is large and bipartite. In other respects their internal parts are like those of Lizards, save that all the intestines are long and narrow. The tongue is narrow, long, black, and very exsertile. It is a peculiarity of Snakes and Lizards that they possess a bifid tongue ; but the points of the tongue of Snakes are fine like hairs. All Snakes are " carcharodont " (have acute teeth) ; they havens many ribs as there are days in the month, viz., 30. Some say that Snakes recover the loss of an eye ; the tail is reproduced in Lizards and Snakes when cut off," &c. Thus accurate statements and descriptions are sadly mixed with errors and stories of, to our eyes, the most absurd and fabulous kind. The most complete accounts are those of the Crocodile (chiefly borrowed from Herodo- tus) and of the Chamaeleon, which Aristotle evidently knew from personal observation, and which he had dis-
