GLOSSAEY. 263 



Mes'entery. [From the Gr. mesos, "middle," and enteron, the "intestine."] 

 A duplicature of the peritoneum covering the small intestine, which 

 occupies the middle or centre of abdominal cavity. 



Mes'oblast. [From the Gr. mesos, " middle," and blastos, a " germ " or 

 " sprout."] The middle layer of the germinal membrane. 



Mesocolon. A duplicature of the peritoneum covering the colon. 



Metab'olism. [From the Gr. metabole, " change."] The changes taking 

 place in cells, whereby they become more complex and contain more 

 force, or less complex and contain less force. The former is construc- 

 tive metabolism, or anabolism ; the latter, destructive metabolism, or 

 katabolism. 



Metacar'pus. [From the Gr. meta, " after," and karpos, the " wrist."] The 

 part of the hand comprised between the icrist and fingers. 



Metatar'sus. [From the Gr. meta, " after," and tarsos, tlie " instej)."] That 

 part of the foot comprised between the instep and toes. 



Metre. [From the Gr. metron, a " measure."] The primary unit of the 

 Metric System. The measure of length from which the units of weiglit 

 and capacity are derived. It is equivalent to 39.37 inches. A milli- 

 metre is one-tliousandth part of a metre. 



Mi'tral. Resembling a mitre. 



Mo'lar. [From the Lat. mola, a "mill."] A term applied to the teeth which 

 bruise or grind the food. 



Molec'ular. Pertaining to molecules. 



Mol'ecule. [From the dim. of Lat. moles, a "mass."] The smallest quantity 

 into which the mass of any substance can physically be divided. A 

 molecule may be chemically separated into two or more atoms. 



Monox'ide. [From the Gr. monos, " single," and " oxide."] A compound 

 containing one atom only of oxygen combined with one of base, or 

 metal. 



Mo'tor Oc'uli. [Lat.] INIover of the eye. 



Moto'rial. That which causes movement. 



Mu'cin. The chief constituent of mucus. 



Mu'cous. A term applied to those tissues that secrete mucus. 



Myocar'dium. [From the Gr. mys, niyos, a "muscle," and kardia, the "heart."] 

 The muscular structure of the heart. 



Myo'pia. [From the Gr. myo, to " contract," and ops, the " eye."] Near- 

 sightedness. 



My'osin. Chief proteid substance of muscle. 



Na'ris, pi. Na'res. [Lat.] A nostril. 



Neurilem'ma. [From the Gr. neuron, a " nerve," and lemma, a " coat " or 



" covering."] Xerve-sheath. 

 Wi'trogen. A colourless gas forming nearly four-fifths of the atmosphere : the 



diluent of the oxygen in the air. Literally, that which generates nitre. 

 Nucle'olus, pi. Nucle'oli. [Dim. of Lat. nucleus, a "kernel."] A smaller 



nucleus witliin the nucleus. 

 Nu'cleus, pi. Nu'clei. [Lat. a " kernel."] A minute vesicle embedded in 



the cell protoplasm (cytoplasm). 



