STRUCTURE.] GLANDS. 161 



But with the gland-head it is different ; the epidermis still 

 retains its small cells, is generally filled with red sap, and 

 appears to enclose red angular bodies. Directly beneath this 

 small-celled epidermis ten or twelve large long columnar cells 

 may be seen, which form the axis of the gland-head; when 

 completely developed they often exhibit in their interior 

 spiral fibres, and allow the spiral tubes of the stalk to run 

 between them. Even in transverse sections there is nothing 

 to be seen of a cavity in the gland-head, and that it is not 

 present may be better seen in those glands which are found 

 on the edges of the leaves of Drosera rotundifolia. Tn this 

 species the glandular hairs are much larger than the others; 

 the stalk is widened at the extremity like a spoon, and on the 

 side of this spoon sits the glandular organ which effects the 

 secretion. 



On the glandular hairs of Drosera there occur here and 

 there on the stalks other small glands consisting of two con- 

 tiguous vesicular cells ; these are filled with green globules, 

 while the other cells of the stalk generally contain red sap. 

 Dr. "Willshire confirms this statement. 



Of the compound glands some are hollow, others solid. 

 They both vary exceedingly in form. The following brief 

 descriptions of the figures at p. 159, will serve to illustrate 

 the subject enough for an introductory work : 



Simple Glands : , a simple stalked gland, from the out- 

 side of the flower of Sinningia barbata ; it consists of a 

 cylindrical cell springing from the epidermis, then of two 

 smaller cells, and finally of a fourth, which is the gland ; 

 b is a gland composed of six cells, of which the two 

 lower are small, cylindrical, and colourless, forming a 

 stalk, the four upper spherical, larger, and filled with 

 secreted matter; d, simple pestle-shaped glands of 

 Sisymbrium chilense; in the pestle there is a yellow 

 volatile oil ; at the base are three cells of the epidermis ; 

 g, from the inside of the under-lip of Antirrhinum 

 majus: the cell containing the glandular matter is at 

 first cylindrical; it then forms a head, from which 

 another cylindrical joint is emitted, to which a second 

 head is afterwards added, and upon which another joint 



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