RUMINAN'TIA (Lat. 'rzi- 'nzinare, to chew the cud), Eng. Ruminants ; Fr. Runzinans ; Ger. Wiederkduende Thiere, a well defined order of mammalian quadrupeds, presenting the following essential characters : Upper jaw in nearly all cases destitute of incisor teeth, their place being supplied by a callous pad, while the lower jaw has six incisives ; canines inconstant ; molars usually six on each side of both jaws, with flattened crowns surmounted by two double and irregularly crescentic folds of enamel. Stomach com pound and divided into four cavities, so as to provide for the ruminating act. Ccecum large. Placenta generally in the form of cotyledons. Feet ungulate and bisulcate.
This order forms two natural divisions, comprising the Hornless ruminants (akera tophora, Col. H. Smith) which are few in number, and the Horned ruminants (kera tophora) which are very numerous. The English naturalist Ray, who was the first to propose a classification based on philosophical principle, enumerated only fifteen species. Pallas subsequently divided the entire family into six genera, and the Baron Cuvier into eight or nine; but the number of subdivisions held to constitute genera by later authorities has been very greatly extended. To serve our present purpose we shall retain only the Linnean and two other genera, which may be conveniently arranged under the five following heads or sub-orders : The Camelidm differ in many. important particulars from the horned ruminants, and exhibit an approximation to the Pachy dermata. The dental formula is peculiar ; thus in the genus Camelus there are, 1 1 2 2 3 3 30 " 3 3 ; e. 1 1 ; P. 1 1 ; 3 3 = and in this respect the Auchenias, or Llamas, disagree only in the number of molars, which is usually fourteen. The distinguishing fea tures of this family depend principally upon the beautiful provision of water-cells in the walls of the paunch or first cavity of the stomach, the absence of horns and the bisulcate feet, which are "callous beneath, and have the toes distinct at the tip from the sole."* The uterine and fcetal membranes
are unprovided with the ordinary ruminant or cotyledonoid form of placenta. Professor Owen has demonstrated another remarkable character arising out of the non-development of foramina for the passage of the vertebral arteries through the transverse processes of the lower six cervical vertebrm. This ana tomical arrangement occurs in no other existing tribe of mammifers, but in an aber rant form of fossil pachyderm (Macrau chenia), Dr. Owen has detected the saine anomaly, and has thus established an ad ditional connecting link between the Pachy dermata and Ruminantia.
In the classification of the Cervidm given above we have included two genera not usually considered as forming a part of this family. One of the principal characters of the Cervidm proper consists in the presence of deciduous' horns or antlers : the genus Moschus, however, like .the Camelidm, is hornless; and the genus Camelopardalis is provided with persistent horns which are at all times clothed with a hairy integument. The dental formula of the Cervidm and all other horned ruminants is usually as fol lows, - 0 0 0 0 3 3 3 3 ; ; p.tn._; 3 3 1 1 S 3 3 3The Musk-deer tribe have in addition two long and conspicuous canines in the upper jaw, projecting in the males below the mouth. (fig. 330.). The male Kijang or Muntjak (Cervus niuntjac, Zimmerman) has likewise two prominent canines in the upper jaw (a, fig. 331.). In the Giraffe there is a complicated glandular and pouch-like struc ture in the neighbourhood of the ileo-colic valve.* The Antelopidm include the greater num ber of the Cavicornua or hollow-horned division of ruminants in which the bony. axis of the horn is solid, persis'ent, and destitute of cavities or pores. They have, for the most part, a slender figure adapted for rapid pro gression, and, like the Stags, are further dis tinguished by the possession of infraor bital glandular sinuses.