pee 6 BQ. 5 5e Sepactnval and 2 
el FF aN om velele nt Ey De Eee a a =: > 
Et NEN medio SEN Bh pe ae OR Pe DERE CAA ae MES, He Wud legs ae 
My 7) <3 Wea ry Fla ge re) tat RRS atti Sede CP } ey ig » a 
Rei OE Ta Od ty NG Gr Stans» i “Tra RMadit one SSNs MAS 7 an go a 
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SPOR. Wd) aes it a aie , 
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| hysiological Botany, ~~ 
“ : 
described as the ‘primogenita ;’ all the functions of the on | 
i. -mother-cell are transferred to it; it grows to be like its 
parent in every respect ; and the same process of division ~- 
is then repeated in it. The building up of the mass of cells 
of which the plant consists results from the division in all 
directions of the remaining daughter-cells (Fig. 83, 1). | 
cy \' 
fat 
ie 
i, Sigel ile Oks 
: a ae 5 wel ey 
aay. D® ae an: Wi ONG S 
LORD) “OR 3 
OO la Of) ls Oaae 
S Cv RE 9) oy g Z 
—™~ 
Sy = 
Fic. 83 I.—External view of the 
Poe in flowering plants—at least in Monocotyledons and 
fe _ Dicotyledons (Fig. 83, 11)—the mode or development is dif- © 
Fig. 82.—I. An Alga, Ulva bulbosa, consisting 
of a single plate of cells ; IJ. Swarmspores 
which have escaped from the empty cells. 
exposed apex of the stem of ~ 
Equisetum scirpoides ; s apical 
cell ; the darker lines indicate 
‘(x about 300.) 
the boundaries of the daughter-cells derived from the apical cell; e.g. 72°, the 
latter being again the mother-cell of those marked 1, 2, 3, 4. (X 350.) 
as ferent. The mother-cell of the embryo here breaks up at 
‘once into a great number of equivalent cells, which again 
ay divide into various groups of cells, each one of these assisting 
‘in building up the structure of the plant, playing the same part 
throughout in the entire course of vegetative development, 
a 
and carrying on its functions independently of the others. 
- The order of succession in the formation of the various 
ee: eroups of cells is as follows :—The first independent tissue 
formed is the epidermal tissue or dermatogen. 
pe 
The layers 
of cells lying immediately beneath then begin todevelopein 
a peculiar manner as cortical tissue or fereblem, the paren- ia 
x -chymatous or primary cortex being formed from them. This “ag 
Nv! 
