MON 



MON 



name given by Rudolphi to those animals 

 which were supposed to possess only the 

 ganglionic system of nerves, as the mol- 

 lusca and the insects. 



18. Mono-petalous {ireraKov, a leaf). 

 Having a single petal, as applied to the 

 corolla of plants. The difference, how- 

 ever, between a mono-petalous and a 

 poly-petalous corolla is, that in the former 

 the leaves are united, whereas in the 

 latter they are distinct. A more proper 

 term for the former is gamo-petalous, 

 which indicates cohesion. 



19. Mono-phyllous {(pvWov, a leaf). A 

 term sometimes employed as synonymous 

 with monosepalous, and denoting cohe- 

 sion of the sepals, or a gamosepalous 

 calyx. 



20. Mcno-pleurobranchians {nXevpa, 

 the side, /Spdfx^a, gills). An order of 

 the Paracephalophora, in which the 

 branchiae are more or less completely 

 covered by a portion of the mantle, and 

 situated on the right side of the body. 



21. Monosepalous. Having a single 

 sepal, or calyx-leaf. The term gamo- 

 sepalous is preferable, for the reason 

 assigned under the term mono-petalous. 



22. Mono-thalamous {OaXafxo^, a cham- 

 ber). A term applied to a shell which 

 forms a single chamber, as that of the 

 argonauta. 



23. Mono-thyra {Ovpa, a door), A term 

 applied by Aristotle to all spiral univalve 

 shells. See Dithyra. 



24. Mono-tremata (rpdo), to bore a 

 hole). An order of Mammalia, charac- 

 terized by the presence of a common 

 cloacal outlet for the excremental and 

 the generative products. They are ovo- 

 viviparous animals, being intermediate 

 between the truly viviparous mammalia, 

 and the oviparous birds and reptiles. The 

 order contains only two species, the 

 echidna or spiny ant-eater, and the orni- 

 thorrhynchus or duck-billed platypus. 



MONAD (/ioi/ar, unity). The smallest 

 of all visible animalcules, spoken of by 

 Buffon and his followers as constituting 

 the elementary molecule of organic 

 beings. Ehrenberg computed that a sin- 

 gle drop of liquid may contain 500,000,000 

 monads, a number equal to that of all 

 the human beings on the surface of the 

 globe. 



1. Monad of the Physiologists. An 

 elementary particle of an organic body. 

 Thus, the primary cell or germ from 

 which all the other cells of the brain are 

 produced, is termed the primary monad ; 

 and the secondary cells or particles, pro- 

 224 



duced by this, are termed secondary 

 monads. 



2. Monad of the Metaphysicians. An 

 active kind of principle, endued with 

 perception and appetite, ascribed to 

 each elementary particle of matter. The 

 mutual reaction of the mind and body 

 upon each other, accordingly, consists of 

 the action of the mental monad upon the 

 internal states of the monads of the body, 

 and vice versa. 



MONGOLIAN RACE. One of the 

 five principal races of mankind, in which 

 the head is almost square, the cheek- 

 bones projecting outwards, the nose flat, 

 the face broad and flattened, with the 

 parts imperfectly distinguished, the in- 

 ternal angle of the eye depressed towards 

 the nose. 



MO'NITOR. An animal of the sau- 

 rian or lizard tribe, some species of 

 which are found in both the fossil and 

 the recent state. 



MONS MENELAUS. A modern 

 northern constellation consisting of 

 eleven stars. 



MONSOO'NS {mooseem, Malay, a sea- 

 son). Periodical winds, which blow 

 half the year from one quarter, and the 

 other half from the opposite direction. 

 From April to October a south-west wind 

 prevails north of the equator, southward 

 of this a south-east wind ; from October 

 to April, a north-east wind prevails north 

 of the equator, and a north-west between 

 the equator and 10° of south latitude. 

 The monsoons occur in the Bay of Ben- 

 gal, the Arabian Sea, the Mozambique 

 Channel, on the coasts of Sumatra and 

 Java, along the coast of China, and off 

 the western coast of New Holland. 



MONTGOLFIER. An air-balloon, or 

 aerostat, made of paper, with a large 

 opening below, where fire is applied for 

 the purpose of rarefying the contained 

 air, until it is of less specific gravity than 

 the atmospheric air. It is named from 

 its inventor. 



MONTH. 1. The average sidereal 

 month, or complete circuit of the hea- 

 vens, comprises a period of 27d. 7h. 4.3m. 

 11.5s. 2. The average lunation, common 

 month, or interval between two conjunc- 

 tions with the sun, consists of 29d. 12h- 

 44m, 2.9s. 3. The average anomalistic 

 month, or revolution from perigee to 

 perigee, consists of 27d. 13h. 18m. 37,4s. 

 4. The average tropical month, or period 

 from the vernal equinox to the vernal 

 equinox again (the equinox being in re- 

 trograde motion), consists of 27d. 7h. 



