CLASSIFICATION OF RECEPTACLES. 263 
(c) As glandular heads of hairs. 
1. Upon the epidermis, glandular hairs of the Labiate. 
Kamala, Glandule Lupuli (colleters). 
2. Projecting into intercellular spaces (Aspidium Filiz 
mas). 
II. Secretion-receptacles produced through the fusion of cells: 
(a) Of rows of cells: latex-tubes (Papaveracee, Cichoriacex, 
Campanulacez). 
(6) Of homogeneous aggregations of cells: lysigenic oil- and 
balsam-passages (Rutacezx, including the Aurantiez). 
(c) Of entire, and also dissimilar portions of tissue: gum- 
glands. 
Ii]. True intercellular spaces : 
(2) Containing oil or resin, schizogenic balsam-passages (in 
the Conifere, Umbellifere,.. Myrtacee, Leguminose, 
Hypericinez). 
(4) Containing gum-resin (the roots of some Umbellifere). 
(c) Containing mucilage, schizogenic mucilage-passages 
(Cycadeze). 
(d) Containing laticiferous juice (Alisma Plantago). 
The secretion receptacles may be profogenic, that is, they may 
be formed already in quite young tissues, or they may be 
hysterogenic, that is produced at a later period in old and com- 
pletely developed tissue. 
In transmitted light, many leaves appear finely punctate in 
consequence of the presence of resin cells, resin cavities, and 
crystal cells. Bokorny has utilized these ‘ pellucid points ” 
diagnostically.?. The pellucid points are caused by resin cells in 
the Lauracew, Piperacee, Meliacex, Sapindacee, Canellaces, 
Anonacex and others, by resin-cavities in the Myrsinee, Myrta- 
cee, Rutacee, and Hypericinex. : 
1 The size of the resin-canals possesses diagnostic value in distinguish- 
ing Rad. Levistici and Angelice. In the former they have the same di- 
ameter as the vessels; in Angelica, on the contrary, they are consider- 
ably wider. 
2 Die durchsichtigen Puncte der Blatter in anatomischer und syste- 
matischer Beziehung.” Flora, 1882. 
