es Se Sin ONS Re Be ORR PO care ce ta a f EGE OE NS Ie ee 
Coal re caer os ishiral had Ph by sioloe Ds, Botany. 
~*~ ane it must be simply the imperfection of our microscopes whch prevents | oe . 
ee us from recognizing that organization which is a necessary accompaniment — 
fee ces of all vital phenomena. One of the most important of these phenomena cstins 
ee is its motility or power of movement, -A 
continuous, even though generally ex- — 
tremely slow and imperceptible, movement 
of the minute particles is inseparable from. 
the idea of life ; and that movements of 
this kind must be especially energetic in 
the case of protoplasm may be inferred 
from its extreme importance to the life of © 
the plant ; although they are usually not 
visible. Perceptible movements are espe- 
cially clearly seen in some of those cells 
—termed primordial cells—which are not 
enclosed in a firm cell-wall; the move- 
ments of the protoplasm being often so ~~ 
vigorous in them that the cells are pro- °-° 
pelled to a considerable distance from their 
original position, and present-to the be- 
ginner the appearance of animal organisms 
endowed with voluntary power of motion. 
Instances of this are furnished by the 
‘swarming’ motion of swarmspores and 
antherozoids, the amceba-like movements 
of the Myxomycetes, &c. Protoplasm 
which is enclosed in a cell-wall has, it is 
true, no power of escaping from its enve- ~ 
lope ; but even in these cases the micro- 
scope shows a ‘streaming’ of the proto- 
| BN Pees Y plasm in all young living cells. The course 
aa aus of the current is usually only along the 
ee SM wall, and in simple spiral or reticulate 
cael lines, and is then termed vzofation, as in 
AS gh ese Chara and Vallisneria ; less often, as in the 
Fig. 3.—Circulation of proto. filaments of 7vadescantia, itpassesin threads 
epee ee plasm in an elongated cell of . 
chi _ the celandine; # the nucleus and bands transversely through the cell- ~~ 
eee vith amicleolus. The arrows 
pie “indicate the direction of the S@Pp,and is then called cé~culaton (Figs 3). 
| currents. (x 460.) The currents are apparently irregular, now. ~~ 
- : 3 advancing, now retreating, sometimes suddenly arrested and commencing __ ‘ 
Nall : again with two-fold rapidity, and again forming for themselves Bee, eS 
- paths through the cell-sap. Braces ps 
a 
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