mesolabe 
the corresponding ilixtimrr on the uppermost rectangle is 
Hi,- L...! multiplied by that of the common altitude of the 
"deli hist is supposed to he known. The ex- 
ernployeil. The mesolalie W;IH invented by Eratosthenes, 
:iinnit -200 to '260 years before Christ, 
mesole (mes'61), n. [< Gr. /rfoof, middle (!).] 
mesolite (mes'o-lit),n. (X Gr. &rof,middle, + /.<- 
MI-, stone.] A zoolitic mineral resembling scole- 
eiie, but containing both calcium and sodium. 
mesolobar (mes'o-16-biir), a. [< mesolobe + 
-r~.] Of or pertaining to the mesolobe; cal- 
losal : as, mesolobar arteries. [Bare.] 
mesolobe (raes'o-lob), n. [< Gr. fttaof, middle, 
-I- /*.o/3of, lobe: see lobe.] The callosum or 
corpus callosum of the brain; the great com- 
missure of the cerebral hemispheres. [Rare 
or obsolete.] 
mesologarithm (mes-o-log'a-ril?Hm), n. [< Gr. 
ftiaof, middle, + E. logarithm.] A logarithm 
of the cosine or cotangent. Kepler. 
mesological (mes-o-loj'i-kal), a. [< mesolog-y + 
-if-nl.] Of or pertaining to mesology ; relating 
to the medium in which an organism exists. 
Grapes contain the mineral salts in variable quantity, 
the proportion depending on the variety of grape and on 
menolor---' ""--- 
meso 
3725 
mesondeut, mesondieut, . See measondue. 
o'fT ' 
, n. 
f, middle, 
The sum 
of human knowledge concerning the relations 
of an organism to its environment. 
mesomeristem (mes-6-mer'is-tem), n. [< Gr. 
^ middle, + E. miristcm.] The innermost 
of the two layers into which the exomenstem is 
divided. The exomeristem is the thickening-ring which 
surrounds the axial strand (primary pith of Sanio) or pith- 
cylinder of the nascent shoots or branches of plants. Iti 
^vas^lS^^ 
rise to the external cortex and the dermatogen. 
mesometric (mes-o-met'rik), a. [< mesometry 
+ -ir.] Of or pertaining to a mesometry or 
mesometrium: as, mesometric folds of perito- 
neum. 
mesometritis (mes'o-me-tri'tis), . [NL.,<Gr. 
uiaoc. middle, + uIJTpa. the womb, + -itis.] In 
pathol., inflammation of the midie or muscu- 
far coat of the uterus. Compare metritti. 
mesometrium (mes-o-me'tri-um), n. ; pi. meso- 
mctria (-it). Same as mesometry. 
mesometry (mes'6-me-tri), . ; pi. mesomelries 
(-triz). \_^L. mesometrium, <QT.^aof, middle, 
intermediate, + /ifrpa, the womb: see matrix.] 
The mesentery of the womb or its annexes; a 
peritoneal fold, holding in place the uterus or 
anoviduct. The broad llgamenf of the human uterus Is 
a mesometry. Corresponding duplications of peritoneum 
acquire special characters in different cases. 
It (the oviduct of a bird) is supported by peritoneal 
The ti*<m^rfc tubules extend gradually from behind 
forward! till they come in contact with the pronephroa. 
Went. Sdm, XJOJL iss. 
me sonephron (mes-o-nef'ron), n.: pi. mego- 
n ci>lira (-rii). [NL., <; Or. /itnof, middle, + ve- 
^nof kidney: see nephritis.] The Wolffian body 
proper; the central or intermediate part of the 
ge gmental organs or primitive renal organs of 
the embryo, between the pronephron and the 
metanephron, whoseduct is the Wolffian duct: 
distinguished from pronephron and metaneph- 
ron> 
mes o ne phros (mes-o-nef ros), n.; pi. mesoneph- 
roi (-roi). [NL.: see menonephron.] Same as 
mesoH ephron. Gray, Anat. (ed. 1887), p. 133. 
m esonotal (mes-o-no'tal), a. [< mesonotum 4- 
^_j situated on'themesonotum; of orpertain- 
j n g to the mesonotum. 
megonotuln (mes-o-no'tum), n. [NL., < Gr. 
fiioof, middle, + vurof, the back.] The middle 
one o f t Qe three divisions of the notum of an 
Jjj 8ec t succeeding the pronotum and preceding 
themetanotum;t1,edorsaldivis i onoftheme 8 o- 
thorax; the upper part of the middle thoracic 
mesopterygium 
mesoplast (n>eH'f>-]>last), n. KGr. ///onr, middle, 
4- r/norof, verbal adj. otir/aaoetv, form, mold.] 
Nuclear protoplasm; endoplast; a cell-nucleus. 
mesoplastic (mes-o-plas'tik), a. [< mesoplagt 
+ -I'e.l Of or pertaining to mesoplast. 
mesoplastraKmes-o-plas'tral), a. [(mesoplM- 
iniii + -fit.] Of or pertaining to the mesoplas- 
tron. 
In the Fleorodlra the first two families are distinguished 
from one another by the presence or absence of a metoplat- 
IraUmae. .\.i'.,,.-. \l. . 
may or ma y no t be distinguishable by means of sutures 
between them. In llymenoptera, Lepidoptera, and Dip- 
It is very large ^forming the principal part of the up- 
!SS?SSrl!Sftt?5ffil 5SS? tataSSlK 
\ ng wing-covers the mesonotum is generally concealed iiy 
them,exceptapiececalledthecuteaum,whichmaybevery 
small.as in most Coleaptera, or large, as in many Hfmiplrra. 
Mesonychidae (mes-o-nik'i-de), n. pi. [NL., 
<^. W ^ + -i^.] A family of mammals hav- 
mg as typo the genus Megoiiyx. 
Mesonyx (mes'o-niks), n. [NL., < Gr. fitaof, 
middle, + owf(oTO^-), nail: see onyx.] A genus 
of fossil carnivorous mammals, based by Cope 
in 1873 upon remains from the Eocene beds of 
Wyoming. It represents a generalized type supposed 
by cope to have some relationship with existing seals. The 
' had * blu . nt f w8 a - d B long Blci : d " **" 
mesoparapteral (mes o-pa-rap te^-ral), i 
i< u*opara,>ter-on + -aJ.] Of or pertaining to 
tne mesoparaiiteron. 
mesoparapteron mes'o-pa-rap te-ron), N ; pi. 
mcsoparaptcra (-ra). [Nt.,< Gr. poof, middle, 
+ ^ L - l>arapteron : seeparapteron.] The pa- 
rapteron of the mesothoracic segment; the 
third scleTite of the mesopleuron. 
mesophlebltis (rae^o-fl|-bl tis), n. NL.,<Gr 
/^""f, BSMWla, t <ptej> (o'-ep-), a vein, -1- -ifis.J 
In pathol., inflammation of the middle coat of 
a vein. 
mesoplastron(mes-o-plas'tron), n. 
middle, + E. plastron.] A median and ante- 
rior bone or plate of the plastron developed in 
certain of the plenrodirous tortoises. 
mesopleural (raes-o-plo'ral), a. [< megopleuron 
+ -al.] In entom.'. intermediate and lateral, as 
a part of the mesothorax ; of or pertaining to 
the mesopleuron. 
mesopleuron (mes-o-pl8'ron), n.; p\.megopleura 
(-r&). [NL., < Gr.>fooc, middle, 4- irteyxSv, a 
rib": see pleura.] The lateral or pleural part 
of the mesothorax of an insect; a mesothoracic 
pleuron, following the propleuron and preced- 
ing the metapleuron. Each mesopleuron, right and 
left, Is divided into three sclerltes an epistemum, an epi- 
Gr. 
, + ^, arms, + Mof (idbrr.) = 
A genus of cetaceans: same as ^- 
phiug. 
mesoplodont (me-sop'lo-dont), a. [< Mcsoplo- 
don(t-).] Armed with a tooth in the middle of 
each side of the lower jaw: said specifically of 
whales of the genus Mexoploaon. 
mesopodia, . Plural of mesopodiuni . 
me80 p O dial (mes-6-po'di-al), a. and II. [< nifgo- 
,/,, + ./.-] 'I. a. l" Of or pertaining to 
g megopodium o f a mollu,k.-fi. Of or^per- 
taming to the mesopodiaha. 
jj_ . Amesopodial bone; one of the meso- 
podialia. 
mesopodialia (mes-o-po-di-a'li-il), n.pl. [NL. 
(Marsh, 1880): see 'megopodium.] The bones 
of the carpus and tarsus, taken together, as 
mu tually corresponding, and as forming mor- 
phological segments of the limbs intervening 
between the epipodialia and the metapodialia. 
gee ** 
mesopodium (mes-o-po'di-um), .; pi. 
W < Gr ; ^ mid ' ( } ] '- 
The middle one of the three parts 
into which the foot of some mollusks, as gistro- 
podg alul pteropods, may be divided, between 
the propodium and the metapodium. See pipo- 
megopos tscutellar (mes'o-post-sku'te-lar), a. 
^ mf^noatxfiitellum + -flrS.J Of or pertaining 
to jj, e m esonostscutellum ' 
Mesomphalia (mes-om-fa'li-ii), n. [NL. (Hope, 
1838), < Gr. fttooc, middle, + o/*paMc, the navel.] 
A genus of beetles of the family Cnrysomelidce. 
They are almost exclusively South American, there being 
over 200 such species, as against one in North America. 
X. consperm Is a South American species with peaked 
elytra, of a blackish-green color punctured with velvety 
black spots, and burnished with six larger golden-haired 
rmps"6 mi 6'dn n / TNL < 
01;, n. m. L^' J -> ^ 
Gr. BPOOC middle + r c, muscle, ^ ^ song.] 
A suborder or other prime division of Pasgeres, 
in which the syrinx is mesomyodian ; non-melo- 
/Umiani-armirloaaTviiaaorinB WrH- (lisHtiOTiishwl 
dious or songlesspassenne birds, aistingmenea 
from Aeromijotli. 
mesomyodian(mes r o-mi-0 dl-an),0. [AS Meso- 
mumli + -i< n 1 1 Havinir the intrinsic svrineeal 
tnohedto th? f,l onlrtofTl 
3 "P^ 
P cr 
Syrinx with less than four distinct pairs of intrinsic 
gan. Coiuw, Key to N. A. Birds, p. 427. 
mesomyodous (mes'6-mi-o'dus), a. [As Meso- 
,,,,,<li + -*.] Same as mesomyodian. 
meson (mes'onV H. [< Gr. iitoov, the middle, 
neut, of ,iiaof = L. medius, middle: see medium, 
wirfi.] 1. The median plane which divides a 
body into two equal and symmetrical parts ; the 
verticallongitiidin;il middle plane, dividing the 
body into right and left halves. Every median 
line lies in the meson. The dorsal bonier of the meson 
is called the darsiineson ; the ventral, sentrimeum. Also 
imuiuin. See mediant, a. 
TIu> incmn. mesal, or median plane is an imaginary Ion- 
and left srmmetrical halve* 
Bwk' HaiuiiM* <>f Mnt. Sdenct*, vill. 536. 
2. Soe tetracliord. 
layer of bark. 
mesophragm (mes'o-fram), n. [NL.: see meso- 
phraama.] Same as mesophragma. 
mesopbragma (mes-o-frag'ma), n.; pi. meso- 
nhragmata (-ma-ta). f< NL. mesophragma, < 
Gr. /ifuof, middle, 4- QpAj/ia, partition: see dia- 
phragm.] 1. In entom., a transverse internal 
partition, descending from the anterior border 
of the metathorax above, between the meso- 
thorax and the metathorax, and serving for the 
attachment of muscles. It probably corre- 
sent. 2. In Crustacea, that process of an en- 
dpsternite (or intersternal apoderae) which is 
directed inward to unite with its fellow and 
form an arch over the sternal canal. See ster- 
nal canal, under sternal. 
mesophragmal (mes-6-frag'mal), a. [< meso- 
l>/i rcii/m + -al.] Pertaining to the mesophragm. 
mesophyl, mesophyll (mes'o-fil), n. [NL., < 
Gr. fttaof, middle, + di'AXov, a leaf .] The paren- mesopraescutum (mes'6-pre-sku'tum), n.; pi. 
middle, + NL. postgcutetium, q. v.j The post- 
scutellum of the mesonotum ; the postscutellar 
sclerite of the mesothorax. 
Mesopotamia!! (mes'o-po-ta'mi-an), a. [< 
Mesopotamia, < Gr. Meaoirora/iia, Mesopotamia 
(see def.), lit. 'the land between the rivers,' < 
filaof, middle, + irora^of, river.] Pertaining to 
Mesopotamia, the region between the rivers 
Tigris and Euphrates in Asia, north of Baby- 
lonia. The name is sometimes extended to in- 
clude Babylonia also Mesopotamlan art, a con- 
venient general name including the kindred arts of ancient 
Chaldea, Babylonia, and Assyria though these arts were 
not definitely limited to Mesopotamia proper. They con- 
stitute together one of the chief divisions of art develop- 
ment, and exerted an important influence upon Greek art, 
and hence upon succeeding arts for all time. See Auyri- 
an, Babylonian, and Chaldean. 
mesopraescutal (mes'o-pre-sku'tal), a. [< 
mesoi>r<rseati<m T -al.] Of or pertaining to tne 
chymatous tissue which lies between the epi- 
dermal layers of a flat leaf-lamina; the soft 
inner tissue of leaves. 
mesophyllum (mes-p-fil urn) n [NL., < Gr. 
&"<*, middle, + fl<Mov, leaf.] Same as meso- 
!>%' ,_ 
mesophytum (me-sof 'i-tum), ,.; pl.mesophyta 
(-) -,L N T L -'< Gr : ^' "i"^ 16 ' + f^\ a 
plant.] In hot., the line of demarcation be- 
tween the internode and the petiole. Lind- 
^ 
m e'sODic (me-sop'ik), a. [< Gr. ufaof, middle, 
+ 3 (^-\ faee-l , HavinK a nasomalar index 
of from I0t.ii to 110, as the negroid races; 
having small and moderately retreating malar 
bones : as, a mesopic face. 
esopraesciltum (mes'o-pre-sku'tum), n.; pi. 
mesvpratscuta (-IS). [NL., < Gr. ^<rof, middle, 
+ NL. fr*****, q. v.] The pnescntum of 
the mesothoracie segment of an insect. 
mesoprosopic (mes-o-pro-sop'ik), a. [< Gr. 
/jtaof, middle, + ir/xiauvw, face.] In craniom., 
intermediate between chamieprosopic and lep- 
toprosopic- that is, with a face o 
^ dth; ^li a facial index of about 90. 
mesopsyche (mos-op-si ke), n. [ Gr. fitaof,rma 
die, + V*'/P7> spirit.] Haeckel's name for the 
niidbrain or mesencephalon. 
mesopterygial (mes-op-te-rij'i-al),a. [(mesop- 
frr,,,,, + -/.] Of or pertaining to the m <*- 
opteryRium. 
mesopterygium (mes-op-te-nj i-nm), n.; pi. 
mcsopterygia (-a). [NL., < Gr. iitaof, middle, + 
