68 COLLECTING HAIRS.—GLANDS. 
which occur on the parts of the flower frequently serve an in- 
direct part in the process of fertilisation by collecting the pollen 
which falls from the anthers ; hence such are termed collecting 
hairs (fig. 158). The collecting hairs, which occur on the style 
of the species of Campanula ( jig. 159, a) are peculiar from their 
upper end, b, retracting within their lower, at the period of fer- 
tilisation. 
Fic. 160. Fie. 161. Fie. 162. Fie. 163: 
Ny @ GR 
Fig. 160. Stalked unicellular gland of Salvia.—Fig. 161. Stalked unicel- 
lular glands of Snapdragon (Antirrhinum majus).—Fig. 162. Stalked 
many-celled gland of Ailanthus glandulosa. From Meyen.— Fig, 163. 
Stalked many-celled gland from Begonia platanifolia. From Meyen. 
(2.) Glands.—This name properly applies only to cells which 
secrete a peculiar matter, but it is also vaguely given to some 
other epidermal and sub-epidermal appendages. Glands have 
been variously arranged by authors ; thus, by some, into exter- 
Fic. 164. Fie. 165. Fic. 166. Fic. 167. 
| 
Fig. 164, Stalked gland of Snapdragon, terminated at its summit by two 
secreting cells.— Fig. 165. Stalked gland with four secreting cells at its 
apex. From Meyen. Fig. 166. Sessile many-celled gland.— Fig. 167. 
One-celled sessile glunds, termed papule or papille. 
nal and internal ; by others, into simple and compound ; while 
others, again, have adopted different modes of arrangement. 
We divide them into external and internal. 
a. External Glands.—These may be again divided into stalked, 
and sessile or not stalked. The stalked glands are those which are 
frequently called glandular hairs (see page 67). They are either 
formed of a single cell, dilated at its apex by the peculiar fluid 
