meridianus 
Mesophytum 
meridia’nus (Lat. belonging to noon), 
at mid-day or noon; towards the 
south (in northern latitudes) ; 
merid‘ian, applied by O. Mueller to 
the plane in Diatoms which con- 
tains the pervalvar axis, 
Mer‘idisk (uépos, a part, dicKos, a disc), 
term proposed by Clos for any 
process upon the receptacle apart 
from the floral organs, whether 
glandular or not (Crozier); Mer’ism, 
Bateson’s term for the repetition of 
parts to form a symmetry or 
pattern. 
merismat’ic (uépicua, a share), divid- 
ing into parts or similar portions ; 
~ Tis’sue, formative tissue, ¢/. 
MERISTEM. 
Mer’ispore (épos, a part, oopd, seed), 
the segment of a sporidesm ; Mer’- 
istele (o77A7, a pillar), a portion of 
the stele of a monostelic stem 
received by each leaf; meris’tic 
Varia’tion, see MERISM. 
Mer‘istem (uepiords, divisible), nas- 
cent tissue, capable of being trans- 
formed into special forms, as cam- 
bium, etc. ; Pri’mary ~, forms the 
whole tissue of very young organs ; 
Sec/ondary ~, occurs in organs 
along with permanent tissue, usually 
in thin layers; meristemat’ic, 
pertaining to the Meristem ; meri- 
stogenet’ic (yevérys, a begetter), 
produced by Meristem, actively 
dividing cell-tissue ; Mer’ithal, 
Merithal’lus (@aAdés, a young 
shoot), an internode. 
meroblas’tic (uépos, a part, Braces, a 
bud) Embryog’eny, when only a part 
of the spore is concerned, ¢/. HOLO- 
BLASTIC ; Meroconid’ium, pl. Mero- 
conid’ia, (+ CoNIpIUM), conidia 
which arise from the simultaneous 
septation of a hypha in Zygomy- 
cetes, and mature together, while 
ACROCONIDIA mature in succession 
from the apex (A. Fischer); meros- 
as a prefix, and its forms -merous, 
-merus, as suffixes, denote parts or 
numbers, as dimerous, etc. 
mes‘arch (yéoos, in the middle, dpyh, 
beginning), applied by Solms-Lau- 
156 
bach to those bundles in which the 
protoxylem lies in the interior of 
the primary strand of the wood, 
thus partly centripetal and partly 
centrifugal ; Mesenter’ica (evrépov, 
an intestine), ‘“‘the mycelium of 
certain Fungals” (Lindley); Mes’- 
istem, contracted from Mesomer’is- 
tem, the thickening ring of Sanio, 
a ring of tissue producing the bundle 
system ; Mes’oblast (S\acros, a bud), 
the nucleus ; Mesoblaste’sis, medial 
growth from Lichen hy phae(Minks); 
Mes‘ocarp, Mesocar’pium (kapros, 
fruit), the middle layer of a 
pericarp ; Mesocauleorhi’za (kavids, 
stem, fifa, root), Gaudichaud’s 
term for ‘‘the line of demarcation 
between the ascending and de- 
scending systems in his ‘Phyta,’” 
(Lindley) ; Mes‘ochil, Mesochil’ium 
(xethos, lip), the intermediate part 
of the lip of those Orchids which 
have it separated into three dis- 
tinct parts; Mes’ochite (yirwv, a 
tunic), the middle layer surround- 
ing the egg in Fucaceae, composed 
of cellulose and attached at the 
base (Farmer) ; Mesocol’la, t (xéAAa, 
glue), asupposed intermediate layer 
of the cuticle between the upper 
and lower surfaces; Mesoder’mis 
(dépua, skin), the middle layer of 
tissue in the theca of a Moss; 
Mesogonid’‘ium (+ GoNIDIUM), a 
gonidium which is partially en- 
veloped in new tissue; mesogon- 
im’icus (yéviuos, productive), having 
the gonidial layer in the centre 
(Wallroth) ; Mesophio’ém (dovds, 
bark), the middle, or green bark ; 
Mes’ophyll, Mesophyl'lum (pvddov, @ 
leaf), (1) the interior parenchyma 
of a leaf, the whole interior ground 
tissue of the blade; (2) the de- 
marcation between leaf and leaf- 
stalk ; Mes’ophyte (gurdv, a plant), 
Warming’s term for those plants 
which are intermediate between 
Hydrophytes and Xerophytes ; 
avoiding both extremes of moist- 
ure and drought; Mesophy’tum, (1) 
a name given by Clarion to the 
