PLANT ORGANS AND ORGANISMS 
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the Epidermal Daughter-cell. The latter, upon maturing, becomes a 
normal epidermal cell. A partition is laid down lengthwise through 
the Stoma Mother-cell dividing it into two stomatal daughter-cells. 
The wall laid down lengthwise splits and thus forms the orifice of the 
stoma; the cells on either side of the orifice are called Guard Cells. 
Fig. 89. —Types of stomatal apparatuses and neighboring cells from different 
sources. In A, a portion of the lower epidermis of Easter Lily leaf. The sto¬ 
matal apparatus is surrounded by neighboring cells that are similar to other 
epidermal cells adjacent to them; in B, lower epidermis of Senna leaflet, note 
the two neighboring cells parallel to the guard cells, one being larger than the 
other; C, lower epidermis of Coca leaf showing two neighboring cells, parallel 
to the guard cells but nearly equal in size as well as papillated regular epidermal 
cells; D, lower epidermis of Pilocarpus showing rounded stomatal apparatus 
and four crescent-shaped neighboring cells; E, lower epidermis of Uva Ursi, 
showing eight neighboring cells arranged radiately around stomatal apparatus; 
F, lower epidermis of Stramonium. 
These, while at first flat and inoperative, soon become bulged and 
crescent-shaped. This mode of development is seen in Squill, 
Hyacinth, Daffodil, Sambucus, Silene, etc. 
Second Type. —After the cutting off of the stomal mother-cell 
there are cut off on either side portions of neighboring epidermal cells 
which form subsidiary cells to the stoma. This condition is seen in 
Graminece, Cyperacece, Juncacece, in various species of Aloe, Musa and 
Proteacece. 
