254 PHARMACEUTICAL BOTANY 
walls, into eight radiating subsidiary cells, as in Maranta bicolor, 
Pothos argyrea, some of Proteacea, etc. 
FrrtH Type.—The “‘stomal mother-cell”? divides once or 
several times before becoming the true mother-cell of the stoma. 
As a result of the divisions there are also formed one or more 
subsidiary cells. This mode of development is seen in the 
Fic. 171.—Types of stomatal apparatuses and neighboring cells from different 
sources. In A, a portion of the lower epidermis of Easter Lily leaf. The stomatal 
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 neighbor- 
ing 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 apparat@s and four crescent- 
shaped neighboring cells; E, lower epidermis of Uva Ursi, showing eight neighbor- 
ing cells arranged radiately around stomatal apparatus; F, lower epidermis of 
Stramonium, 
Labiate, Papilionacee, Crucifere, Solanacea, Crassulacea, Cuactacea, 
and Begoniacee, also in a number of ferns. 
HisTo.ocic DirFERENCES BETWEEN LEAVES OF DicOTYLEDONS 
anD Monocotytepons.—The following may be cited as broad 
comparative histologic differences between Dicotyl and Mono- 
cotyl leaves: 
