planiusculus 
Plastin 
divides an object into symmetrical 
ae 3 Planius’culus (Lat.), nearly 
at. 
Planktol’ogy (mAay«rds, wandering, 
doyos, a discourse), the department 
of pelagic botany, that is, of the 
floating organisms in the ocean; 
Plank’ton, free-swimming or float- 
ing oceanic life; fresh’water ~, 
that of lakes or rivers; nerit/ic~, 
found near the coast; ocean’ic ~, 
pelagic, far from land. 
Plan/ogamete (zAdvos, wandering, 
yapuérns, aspouse), a mobile ciliated 
gamete or zoogamete, as in Chloro- 
phyceae ; Plan’ospore (o7opi, a 
seed), Sauvageau’s term for a 
motile zoospore. - 
Plant, Plan'ta, a vegetable production 
nourished by gases or liquids and 
not ingesting solid particles of 
food (except in the plasmodial 
stage of Myxogastres); ~ Cane, 
the first year’s growth of the sugar- 
cane from seed; ~ Cas’ein, a sub- 
stance akin to animal casein; ~ 
Forma’tion, an assemblage of plants 
living together in a community 
under the same environment, as a 
moor or wocd; ~ Pathol’ogy, the 
study of plant-diseases; Plan’tae 
tris’tes, evening flowering plants, 
as Matthiola bicornis, DC., etc.; 
plan’tal, pertaining to plants; 
Plan’ticle, the embryo in a seed ; 
Plan’tlet, a little plant; Plan’tule, 
Plan'tula = PLUMULE; Plantula’tio 
= GERMINATION, 
Plasm, Plas’ma (7rAdoya, that formed), 
used for PRoTOPLASM ; Plasmamoe’- 
bae (+ AmoEBA), amoebiform 
masses of protoplasm, the actino- 
phrydia of Gobi; plasmatop’arous 
(pario, I bring forth), in germina- 
tion the whole of the protoplasm 
of a gonidium issues as a rounded 
mass, which at once becomes coated 
with a membrane, and puts out a 
germ-tube ; Plas’masome, or Plas- 
mat’osome (cwpa, a body), a proto- 
lasmic corpuscle, shortened to 
LASOME; plasmat/ic, ready, or 
serving for growth, plastic; Plas’- 
199 
mode = PLASMODIUM ; Plasmo’diae, 
Caruel’s term for Myxogastres ; 
plasmo’dial, plasmo’dic, pertaining 
to a plasmodium ; Plasmo’diocarp, 
(kapros, fruit), an asymmetrical 
sporangium of Myxogastres (Rosta- 
finski) ; Plasmo’diogens  (yévos, 
race, offspring), Macmillan’s word 
for the protoplasmic units of a 
plasmodium ; _ plasmodioph’orus 
(gopéw, I carry), producing a true 
plasmodium ; Plasmo’dium, a mass 
of naked much-nucleated proto- 
plasm, showing amoeboid move- 
ments ; aggrega'ted ~, the myxa- 
moebae congregated without fusion, 
each cell giving rise to a spore or 
foot-cell ; fused ~, union of myxa- 
moebae and subsequent fructifica- 
tion (Van Tieghem) ; Plasmol’ysis 
(Avots, a loosing), a separation of 
the living protoplasm from the 
cell- wall by osmotic action ; 
plas’molysed, subjected to plasmo- 
lysis; adj. plasmolyt‘ic; plasmo- 
ph’agous (¢dyw, I eat), absorbing 
the living organic matter of the 
host-plant without selection (Boul- 
ger); Plasmosyn’agy (cvvdyw, I 
collect), accumulation of the pro- 
toplasts of the polioplasm and of 
the plastids included in it, due to 
plasmolytic irritation (Tswett) ; 
Plas‘ome, a living element of pro- 
toplasm, shortened from PiLasma- 
TOSOME (Wiesner) ; plas’tic, capable 
of being moulded or modified; ~ 
Sub’stances, those employed in 
building up, as cellulose, starch- 
grains, proteids, etc. ; Plastic’ity, 
the quality of being plastic; Plas’tid, 
Plastid'ium, a protoplasmic granule 
in active cells, differentiated as 
centres of chemical or vital activity, 
as CHLORO-, CHRomo-, and Lxv- 
COPLASTID; Plas'tidplasm, ( + 
PLasM), a supposititious substance 
differing from other forms of pro- 
toplasm by morphological charac- 
ters (B. M. Davis); Plas’tidule, 
Elsberg’s term for the smallest 
mass of protoplasm which can exist 
as such; Plas’tin, an essential ele- 
