MES 



260 



MES 



like manner when in water, and 

 closing when dry. 

 mesencephalon, n., m&ftt*0$^4Z- 



on (Gr. mesos, middle ; engkeph- 

 dlon, the brain), the middle 

 primary vesicle of the brain, 

 forming one of its principal 

 structures, and comprising the 

 Crura cerebri, the Corpora 

 quadrigemina, and the Aqueduct 

 of Sylvius. 



mesentery, n. , mfc$ntfrlj mesen- 

 teries, n. plu. , -t&r'fa (Gr. mesos, 

 middle ; enteron, an intestine), a 

 membrane in the cavity of the 

 abdomen which serves to retain 

 the intestines and their appen- 

 dages in their position ; a double 

 fold of the peritoneum ; the 

 vertical plates which divide the 

 somatic cavity of a sea-anemone 

 into chambers : mesenteric, a., 

 mezf-en'terfik, of or belonging to 

 the mesentery : mesenteritis, n. , 

 m^z-en'-ter-lt'-is, inflammation of 

 the mesentery. 



mesial, a., mezf-i-al (Gr. mesos, 

 middle), in anat. , middle ; divid- 

 ing into two equal parts : mesial 

 line, an imaginary plane dividing, 

 from top to bottom, the head, 

 neck, and trunk into right and 

 left similar halves. 



mesocsecum, n. , mez'o-sek'um (Gr. 

 mesos, middle ; L. ccecum, a 

 portion of the large intestines), 

 in anat., a duplicature of the 

 peritoneum at the posterior part 

 of the caecum, which series to 

 connect the back part of the 

 csecum with the right iliac fossa. 



mesocarp, n., mez'-o-kdrp (Gr. 

 mesos, middle ; kdrpos, fruit), 

 in fat*, the middle layer of 

 the pericarp or coat of the 

 fruit. 



mesocephalon, n., m&tfo-sVf'-ftl-dn, 

 or -Mf'-dl-on (Gr. mesos, middle ; 

 kephale, the head), in anat., an 

 eminence of transverse fibres above 

 and in front of the medulla oblong- 

 ata, below and behind the Crura 

 cerebri, and between the lobes 



of the cerebellum ; also called the 

 Pons Varolii. 



mesochilium, n., mez'-o-Jctt'i'tim 

 (Gr. mesos, middle ; cheilos, a 

 lip), in bot., the middle portion 

 of the labellum of orchids. 



mesocolon, n., mez'-o-'kol'-on (Gr. 

 mesos, middle ; Eng. colon), in 

 anat., that part of the mesentery 

 to which the colon is attached. 



mesogastrium, n., mez'-o-gas'-tri- 

 um (Gr. mesos, middle ; gaster, 

 the belly), in anat. , the umbilical 

 region of the abdomen ; a sus- 

 pensory band of the stomach in 

 early embryonic life, subsequently 

 converted into a sac, called the 

 ' great omentum ' : mesogastric, 

 a., m&z'-d-gas'-trik, that which 

 attaches the stomach to the walls 

 of the abdomen. 



mesophloaum, n. , i m&z f >o*fl&um 

 (Gr. mesos, middle ; phloios, 

 bark), in bot., the middle layer 

 of the bark, situated between the 

 liber and epiphlseum. 



mesophyllum, n. , m&z f -d-fil f >lum 

 (Gr. mesos, middle ; phullon, a 

 leaf), in bot., all the inner portion 

 or parenchyma of leaves, situated 

 between the upper and under 

 epidermis. 



mesopodium, n., m%z'd'p6d'-i-um 

 (Gr. mesos, middle ; podes, feet), 

 the middle portion of the foot of 

 Molluscs. 



mesorchium, n. , mez-tirk'i-um (Gr. 

 mesos, middle ; orchis, a testicle), 

 a fold of the peritoneum which, 

 in the fifth month of foetal life, 

 supports the testicle in its position 

 in the lumbar region before it 

 passes into the scrotum. 



meso-rectum, n., mez'-O'rek'tum, 

 (Gr. mesos, middle ; Eng. rectum), 

 a narrow fold of the peritoneum 

 which connects the upper part 

 of the rectum with the front of 

 the sacrum. 



mesosperm, n., m&z'o-sperm (Gr. 

 'mesos, middle ; sperma, seed), in 

 bot., the second membrane, or 

 middle coat of a seed. 



