64 
ORGANOGRAPHY. 
BOOK I. 
They are particularly numerous, and highly developed, upon 
the petioles and the backs of the leaves of Ferns. They con- 
sist of cellular tissue alone, without any vascular cords, and 
are known from leaves not only by their anatomical struc- 
ture, but also by their irregular position, and by the absence 
of buds from their axils. The student must particularly re- 
mark this, or he will confound with them leaves having a 
ramentaceous appearance, such as are produced upon the 
young shoots of Pinus. Link remarks, that they are very 
similar in structure to the leaves of mosses. The term striga 
has occasionally been applied to them (Dec. The or. EUm. ed. 2. 
376. Linh^ Elem. 240.) ; but |,that word was employed by 
Linnaeus to designate any stiff bristle-like process, as the spines 
of the Cactus, the divaricating hairs of Malpighia, and the 
stiff stellated hairs of Hibiscus. So vague an application of 
the term is very properly avoided at the present day, and the 
substantive is rejected from modern glossology; the adjective 
term strigose is, however, occasionally still employed to ex- 
press a surface covered with stiff hairs. 
5. Of Glands. 
Fig. 16. 
Glands are small collections of firm cellular tissue, which 
is often much harder and more coloured than that which sur- 
rounds it. They are of several kinds. 
